Syntheses and characterizations of palladium-based molecular triangle/square compounds and hybrid composites with polyoxometalates

Syntheses and characterizations of a Pd-based molecular triangle and square and hybrid composites with polyoxometalates are examined. The equilibrium between the Pd-based molecular triangle [(en*)Pd(4,4'-bpy)]3(NO3)6 and square [(en*)Pd(4,4'-bpy)]4(NO3)8 largely depends on the solvents, and both compounds have successfully been isolated: [(en*)Pd(4,4'-bpy)]3(NO3)6.3.5DMSO, monoclinic Cc (No. 9), a = 19.8210(2) A, b = 34.3667(5) A, c = 27.5484(4) A, beta = 89.9420(10) degrees , V = 18765.5(4) A3; [(en*)Pd(4,4'-bpy)]4(NO3)8, monoclinic C2/c (No. 15), a = 45.6921(16) A, b = 8.7721(8) A, c = 36.719(3) A, beta = 126.509(2) degrees , V = 11829.4(14) A3. The reactions of the Pd-based molecular triangle/square with [W6O19]2-, [W10O32]4-, and [alpha-SiW12O40]4- form [[(en*)Pd(4,4'-bpy)]4[ supersetW6O19]][W6O19]3, [[(en*)Pd(4,4'-bpy)]4[ supersetW6O19]](NO3)6, [[(en*)Pd(4,4'-bpy)]4[ supersetW10O32]][W10O32], [(en*)Pd(4,4'-bpy)]4[W10O32]2, and [(en*)Pd(4,4'-bpy)]4[alpha-SiW12O40]2. The molecular square does not encapsulate the largest [alpha-SiW12O40]4-, but it does encapsulate [W6O19]2- and [W10O32]4-. The isolation of [W6O19]2- and [alpha-SiW12O40]4- from the mixture by use of the molecular square is possible by utilizing the quite different solubility of [[(en*)Pd(4,4'-bpy)]4[ supersetW6O19]](NO3)6 and [(en*)Pd(4,4'-bpy)]4[alpha-SiW12O40]2 formed in DMSO. The size-selective encapsulation property of supramolecules may open the new way to rationalize isolation methods of the useful polyoxometalates.     

Studies of dirhodium(II) tetra(trifluoroacetate). 5. Remarkable examples of the ambidentate character of dimethyl sulfoxide

The ambidentate character of dimethyl sulfoxide, already known for dirhodium carboxylates, has been remarkably manifested in new ways. Three novel complexes of dirhodium(II) tetra(trifluoroacetate) with the DMSO ligand, namely, [Rh2(O2CCF3)4]m(DMSO)n with m:n = 7:8 (1), 1:1 (2), and 3:2 (3), have been obtained by deposition from the vapor phase, and their crystal structures have been determined by X-ray crystallography. The crystallographic parameters are as follows: for 1, monoclinic space group P2(1)/c with a = 28.261(2) A, b = 16.059(4) A, c = 17.636(2) A, beta = 92.40(4) degrees, and Z = 2; for 2, triclinic space group P1 with a = 8.915(2) A, b = 10.592(2) A, c = 11.916(2) A, alpha = 84.85(1) degrees, beta = 88.86(1) degrees, and gamma = 65.187(8) degrees, and Z = 2; and for 3, triclinic space group P1 with a = 8.876(2) A, b = 9.017(2) A, c = 19.841(3) A, alpha = 101.91(2) degrees, beta = 97.144(8) degrees, gamma = 100.206(9) degrees, and Z = 1. In the oligomeric molecule of 1, six DMSO ligands bridge seven dirhodium tetra(trifluoroacetate) units in a bidentate fashion via S and O atoms, and two additional DMSO molecules terminate the chain. In the structure of the monoadduct Rh2(O2CCF3)4(DMSO) (2), the dirhodium blocks are bridged through the O atoms of DMSO ligands, forming a one-dimensional polymeric chain. Compound 3 also has an infinite chain structure with the molecules of dimethyl sulfoxide acting in a bidentate mu-DMSO-S,O mode. Every second DMSO molecule is missing in 3, so that two of every three Rh2(O2CCF3)4 units are associated through the O atoms of carboxylate groups to give the overall composition [Rh2(O2CCF3)4]3(DMSO)2.     

Cyanide-bridged lanthanide(III)-transition metal extended arrays: interconversion of one-dimensional arrays from single-strand (type A) to double-strand (type B) structures. Complexes of a new type of single-strand array (type C)

A series of one-dimensional arrays of lanthanide-transition metal complexes has been prepared and characterized. These complexes, [(DMF)(10)Ln(2)[Ni(CN)(4)](3)](infinity), crystallize as linear single-strand arrays (structural type A) (Ln = Sm, 1a; Eu, 2a) or double-strand arrays (structural type B) (Ln = Sm, 1b; Eu, 2b) depending upon the conditions chosen, and they are interconvertible. The single-strand type A structure can be converted to the double-strand type B structure. When the 1b and 2b type B crystals are completely dissolved in DMF, their infrared spectra are identical to the infrared spectra of 1a and 2a type A crystals dissolved in DMF. These solutions produce type A crystals initially. It is believed that formation of the type A structure is kinetically favored while the type B structure is thermodynamically favored for lanthanide-nickel complexes 1 and 2. On the other hand the complex [(DMF)(10)Y(2)[Pd(CN)(4)](3)](infinity), 3, appears to crystallize only as the double-strand array (type B). The complexes [(DMF)(12)Ce(2)[Ni(CN)(4)](3)](infinity), 4, and [(DMF)(12)Ce(2)[Pd(CN)(4)](3)](infinity), 5, crystallize as a new type of single-strand array (structural type C). This structural type is a zigzag chain array. Crystal data for 1a: triclinic space group P1, a = 10.442(5) A, b = 10.923(2) A, c = 15.168(3) A, alpha = 74.02(2) degrees, beta = 83.81(3) degrees, gamma = 82.91(4) degrees, Z = 2. Crystal data for 1b: triclinic space group P1, a = 9.129(2) A, b = 11.286(6) A, c = 16.276(7) A, alpha = 81.40(4) degrees, beta = 77.41(3) degrees, gamma = 83.02(3) degrees, Z = 2. Crystal data for 2a: triclinic space group P1, a = 10.467(1) A, b = 10.923(1) A, c = 15.123(1) A, alpha = 74.24(1) degrees, beta = 83.61(1) degrees, gamma = 83.13(1) degrees, Z = 2. Crystal data for 2b: triclinic space group P1, a = 9.128(1) A, b = 11.271(1) A, c = 16.227(6) A, alpha = 81.36(2) degrees, beta = 77.43(2) degrees, gamma = 82.99(1) degrees, Z = 2. Crystal data for 3: triclinic space group P1, a = 9.251(3) A, b = 11.193(4) A, c = 16.388(4) A, alpha = 81.46(2) degrees, beta = 77.18(2) degrees, gamma = 83.24(3) degrees, Z = 2. Crystal data for 4: triclinic space group P1, a = 11.279(1) A, b = 12.504(1) A, c = 13.887(1) A, alpha = 98.68(1) degrees, beta = 108.85(1) degrees, gamma = 101.75(1) degrees, Z = 2. Crystal data for 5: triclinic space group P1, a = 11.388(3) A, b = 12.614(5) A, c = 13.965(4) A, alpha = 97.67(3) degrees, beta = 109.01(2) degrees, gamma = 101.93(2) degrees, Z = 2.     

A convergent synthetic approach using sterically demanding aryldipyrrylmethanes for tuning the pocket sizes of cofacial bisporphyrins

Meso substitution opposite to the spacer provides a convenient approach for tuning the pocket sizes of pillared cofacial bisporphyrins. The synthesis and coordination chemistry of xanthene and dibenzofuran anchored platforms structurally modified with 2,6-dimethoxyaryl groups are described. Comparative structural analysis of xanthene derivatives confirms the ability of the trans-aryl groups to adjust the vertical dimension of the cofacial cleft: 7 (C(97)H(106)Cl(4)N(8)O(5)), monoclinic, space group P2(1)/c, a = 28.8353(12) A, b = 17.1139(7) A, c = 17.5978(7) A, beta = 98.826(1) degrees, Z = 4; 8 (C(101)H(123)Cl(2)N(8)O(11.5)Zn(2)), monoclinic, space group P2(1)/n, a = 14.5517(6) A, b = 22.9226(10) A, c = 28.5155(13) A, beta = 90.312(14) degrees, Z = 4; 12 (C(99)H(102)Cl(14)N(8)O(5)Mn(2)), monoclinic, space group P2/c, a = 19.5891(3) A, b = 15.0741(2) A, c = 33.2019(6) A, beta = 91.947(10) degrees, Z = 4. The convenience and versatility of this synthetic method offers intriguing opportunities to specifically tailor the binding pockets of cofacial bisporphyrins for the study of small-molecule activation within a proton-coupled electron transfer framework.     

Synthesis and characterization of novel rhenium(V) tetradentate N2O2 Schiff base monomer and dimer complexes

Several rhenium(V) oxo complexes with tetradentate N(2)O(2) Schiff base ligands were synthesized and characterized. The general synthetic procedure involved reaction of [NBu(4)][ReOCl(4)] with a tetradentate Schiff base ligand (L(1) = N,N'-ethylenebis(acetylacetoneimine), (acac(2)en) or L(2) = N,N'-propylenebis(acetylacetoneimine) (acac(2)pn)) in ethanol solution to generate complexes of the form trans-ReOX(L) where X = Cl(-), MeO(-), ReO(4)(-), or H(2)O. The product isolated from the reaction was found to be dependent on the reaction conditions, in particular the presence or absence of water and/or base. The mu-oxo-Re(2)O(3)(L)(2) dimers were synthesized and characterized for chemical and structural comparison to the related monomers. Conversion of the monomer to its dimer analogue was followed qualitatively by spectrophotometry. The complexes were characterized by (1)H and (13)C NMR, UV-vis, and IR spectroscopy, elemental analysis, and single crystal X-ray diffraction. The crystallographic data reported for the structures are as follows: trans-[ReO(OH(2))(acac(2)en)]Cl (H(20)C(12)ClN(2)O(4)Re) 1, triclinic (Ponemacr;), a = 7.2888(6) A, b = 9.8299(8) A, c = 10.8195(9) A, alpha = 81.7670(10) degrees, beta = 77.1510(10) degrees, gamma = 87.6200(10) degrees, V = 747.96(11) A(3), Z = 2; trans-[ReO(OReO(3))(acac(2)en)] (H(18)C(12)N(2)O(7)Re(2)) 2, monoclinic (P2(1)/c), a = 7.5547(4) A, b = 8.7409(5) A, c= 25.7794(13) A, beta = 92.7780(10) degrees, V = 1700.34(16) A(3), Z = 4; trans-[ReOCl(acac(2)pn)] (H(20)C(13)N(2)O(3)ClRe) 3, monoclinic (P2(1)/c), a = 8.1628(5) A, b = 13.0699(8) A, c = 28.3902(17) A, beta = 97.5630(10) degrees, V = 3002.5(3) A(3), Z = 8; trans-[ReO(OMe)(acac(2)pn)] (H(23)C(14)N(2)O(4)Re) 4, monoclinic (P2(1)/c), a = 6.7104(8) A, b = 27.844(3) A, c = 8.2292(9) A, beta = 92.197(2) degrees, V = 1536.4(3) A(3), Z = 4; trans-[mu-oxo-Re(2)O(3)(acac(2)en)(2)] (H(36)C(24)N(4)O(7)Re(2)) 5, monoclinic (P2(1)/n), a = 9.0064(5) A, b = 12.2612(7) A, c = 12.3695(7) A, beta = 90.2853(10) degrees, V = 1365.94(13) A(3), Z = 2; and trans-[mu-oxo Re(2)O(3)(acac(2)pn)(2)] (H(40)C(26)N(4)O(7)Re(2)) 6, monoclinic (P2(1)/n), a = 9.1190(5) A, b = 12.2452(7) A, c = 12.8863(8) A, beta = 92.0510(10) degrees, V = 1438.01(14) A(3), Z = 2.     

Two versatile N,N'-bipyridine-type ligands for preparing organic-inorganic coordination polymers: new cobalt- and nickel-containing framework materials

The Schiff base ligands 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene (L1, monoclinic, P2(1)/c, a = 3.856(1) A, b = 11.032(2) A, c = 12.738(3) A, beta = 92.21(3) degrees, Z = 2) and 2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene (L2, monoclinic, P2(1)/c, a = 10.885(2) A, b = 4.613(1) A, c = 14.978(3) A, beta = 92.827(4) degrees, Z = 2) were used in the synthesis of four new organic-inorganic coordination polymers, each of them adopting a different structural motif. Synthesis, X-ray structural determinations, and spectroscopic and thermogravimetric analyses are presented. The reaction between Co(NO(3))(2).6H(2)O and L1 afforded a two-dimensional noninterpenetrating brick-wall structure, [Co(C(12)N(4)H(10))(1.5)(NO(3))(2)(H(2)O)(CH(2)Cl(2))(2)](n)() (1, triclinic, P1; a = 10.242(7) A, b = 10.802(7) A, c = 15.100(1) A, alpha = 70.031(1), beta = 75.168(11), gamma = 76.155(11), Z = 2), while Ni(NO(3))(2).6H(2)O combined with L1 yielded an interpenetrating three-dimensional rhombus-grid polymer, [Ni(C(12)N(4)H(10))(2)(NO(3))(2)(OC(4)H(8))(1.66)(H(2)O)(0.33)](n) (2, monoclinic, C2/c; a = 20.815(8) A, b = 23.427(8) A, c = 17.291(6) A, beta = 116.148(6), Z = 8). The reaction of Co(NO(3))(2).6H(2)O and L2 was found to be solvent-sensitive and resulted in the formation of two different noninterpenetrating compounds: [Co(C(14)N(4)H(14))(2)(NO(3))(2)(C(6)H(6))(1.5)](n)() (3, monoclinic, C2/c; a = 22.760(2) A, b = 21.010(3) A, c = 25.521(2) A, beta = 97.151(2), Z = 8), which adopts a two-dimensional square-grid motif formed by propeller-type modules, and [Co(C(14)N(4)H(14))(1.5)(NO(3))(2)(CH(2)Cl(2))(2)](n)() (4, monoclinic, P2(1)/n; a = 14.432(2) A, b = 14.543(8) A, c = 15.448(4) A, beta = 96.968(0), Z = 4), consisting of T-shaped building blocks assembled into a one-dimensional ladder-type structure. These four coordination polymers all exhibit impressive thermal stability. Thermogravimetric studies showed that after complete removal of the solvents, the frameworks are stable to temperatures between 234 degrees C and 260 degrees C.     

Diverse solid-state and solution structures within a series of hexaamine dicopper(II) complexes

Mono- and dicopper(II) complexes of a series of potentially bridging hexaamine ligands have been prepared and characterized in the solid state by X-ray crystallography. The crystal structures of the following Cu(II) complexes are reported: [Cu(HL3)](ClO4)(3), C11H31Cl3CuN6O12, monoclinic, P2(1)/n, a = 8.294(2) A, b = 18.364(3) A, c = 15.674(3) A, beta = 94.73(2) degrees, Z = 4; ([Cu2(L4)(CO3)](2))(ClO4)(4).4H2O, C40H100Cl4Cu4N12O26, triclinic, P1, a = 9.4888(8) A, b = 13.353(1) A, c = 15.329(1) A, alpha = 111.250(7) degrees, beta = 90.068(8) degrees, gamma = 105.081(8) degrees, Z = 1; [Cu2(L5)(OH2)(2)](ClO4)(4), C13H36Cl4Cu2N6O18, monoclinic, P2(1)/c, a = 7.225(2) A, b = 8.5555(5) A, c = 23.134(8) A, beta = 92.37(1) degrees, Z = 2; [Cu2(L6)(OH2)(2)](ClO4)(4).3H2O, C14H44Cl4Cu2N6O21, monoclinic, P2(1)/a, a = 15.204(5) A, b = 7.6810(7) A, c = 29.370(1) A, beta = 100.42(2) degrees, Z = 4. Solution spectroscopic properties of the bimetallic complexes indicate that significant conformational changes occur upon dissolution, and this has been probed with EPR spectroscopy and molecular mechanics calculations.     

Structurally reinforced tetraazamacrocyclic complexes

The reaction between alkyl or aryl aldehydes and macrocyclic ligands with pendant amine groups produced imidazolidine-containing bi- or tricyclic ligands. The copper complexes of three of these ligands were structurally characterized: [CuL3Cl].3H2O (triclinic, P1, a = 10.041(2) A, b = 10.172(1) A, c = 11.202(1) A, alpha = 92.07(1) degrees, beta = 96.76(2) degrees, gamma = 92.99(1) degrees, Z = 2), [Cu(H2L4)Cl]Cl.2H2O (monoclinic, P2(1)/n, a = 15.159(5) A, b = 10.645(1) A, c = 19.094(6) A, beta = 93.78(1) degrees, Z = 4), [CuL5].2H2O.NaNO3 (monoclinic, P2(1)/n, a = 10.649(8) A, b = 7.261(2) A, c = 15.25(1) A, beta = 94.77(4) degrees, Z = 2). The conformational rigidity and stereochemical activity of these macrocycles and their complexes are discussed in comparison with close analogues.     

Lanthanide chalcogenolate complexes: synthesis and crystal structures of the isoleptic series [Sm(TpMe,Me)2ER] (E = O, S, Se, Te; TpMe,Me = tris-3,5-dimethylpyrazolylborate)

A series of lanthanide complexes containing a chalcogenolate ligand supported by two TpMe,Me (tris-3,5-dimethylpyrazolylborate) groups has been prepared and crystallized and provides direct comparisons of bonding to hard and soft ligands at lanthanide centers. Reaction of [Sm(TpMe,Me)2Cl] with NaOR (R = Ph, Ph-Bu(t)) gives [Sm(TpMe,Me)2OR] (1a and 1b, respectively) in good yields. Reductive cleavage of dichalcogenides by samarium(II) was used to prepare the heavier congeners. Complexes of the type [Sm(TpMe,Me)2ER] for E = S, R = Ph (2a), E = S, R = Ph-4-Me (2b), E = S, R = CH2Ph (2c), E = Se, R = Ph (3a), E = Se, R = Ph-4-Bu(t) (3b), E = Se, R = CH2Ph (3c), and E = Te, R = Ph (4) have been prepared together with the corresponding complexes with TpMe,Me,4-Et as ancillary. The X-ray crystal structures of 1b, 2b, 3a, 3b, and 4 have been determined. The crystal of 1b (C40H57B2N12OSm.C7H8) was monoclinic, P2(1)/c, a = 10.6845(6) A, b = 18.5573(11) A, c = 24.4075(14) A, beta = 91.616(2) degrees, Z = 4. The crystal of 2b (C37H51B2N12SSm) was monoclinic, P2(1)/n, a = 15.0154(9) A, b = 13.1853(8) A, c = 21.1254(13) A, beta = 108.628(2) degrees, Z = 4. The crystal of 3a (C36H49B2N12SeSm.C7H8) was triclinic, P1, a = 10.7819(6) A, b = 19.3011(10) A, c = 23.0235(12) A, alpha = 79.443(2) degrees, beta = 77.428(2) degrees, gamma = 89.827(2) degrees, Z = 4. The crystal of 3b (C40H57B2N12SeSm) was triclinic, P1, a = 10.1801(6) A, b = 10.2622(6) A, c = 23.4367(14) A, alpha = 88.313(2) degrees, beta = 86.268(2) degrees, gamma = 62.503(2) degrees, Z = 2. The crystal of 4 (C36H49B2N12TeSm.C7H8) was monoclinic, P2(1)/c, a = 18.7440(10) A, b = 10.3892(6) A, c = 23.8351(13) A, beta = 94.854(2) degrees, Z = 4. The compounds form an isoleptic series of seven-coordinate complexes with terminal chalcogenolate ligands. Examination of 1b and other crystallographically characterized lanthanide alkoxides suggests that there is little correlation between bond angle and bond length. The structures of 3a and 3b, however, contain molecules in which one of the pyrazolylborate ligands undergoes a major distortion arising from twisting around a B-N bond so as to give an effectively eight-coordinate complex with pi-stacking of the phenyl group with one pyrazolyl ring. These distortions shed light on the fluxionality of these systems.     

Photochemical and chemical oxidation of alpha-dimine-dithiolene metal complexes: insight into the role of the metal atom

[Pd(bpy)(bdt)], 2 (bpy = 2,2'-bipyridine, bdt = 1,2-benzenedithiolate), was prepared in good yield by the reaction of bdtNa2 with [(bpy)PdCl2] in DMSO. The analogous nickel complex, 1, was prepared in a similar reaction using MeOH/CH2Cl2 and [(bpy)NiCl2.dmf]2. Both 1 (a = 7.9920(1) A, b = 11.4385(1) A, c = 16.1415(1) A, beta = 103.327(1) degrees, V = 1435.86(2) A3, Z = 4) and 2 (a = 8.1631(5) A, b = 11.4379(7) A, c = 16.2475(10) A, beta = 103.7010(10) degrees, V = 1473.84(12) A3, Z = 4) crystallize in the monoclinic space group P2(1)/c and are isostructural with their previously reported platinum analogue. In accord with the results observed for platinum but not nickel, photochemical oxidation of 2 in DMF provides the monosulfinate complex [Pd(bpy)(bdtO2)], 4, along with a minor amount of the corresponding disulfinate [Pd(bpy)(bdtO4)], 5, while chemical oxidation yields only the latter. 4 cocrystallizes with 5 in the monoclinic space group P2(1)/c (a = 8.026(3) A, b = 14.600(6) A, c = 13.371(3) A, beta = 101.80(3) degrees, V = 1533.8(9) A3, Z = 4) as does pure 5 (a = 8.5611(9) A, b = 14.4586(15) A, c = 13.3677(14) A, beta = 108.122(2) degrees, V = 1572.6(3) A3, Z = 4). Comparison of spectroscopic and electrochemical properties of the three complexes, [M(bpy)(bdt)], yields the following ordering for the energy of the HOMO: Pd < Ni < Pt. The observed reactivity patterns and the electronic data suggest that the "anomalous" reactivity of 1 be attributed to the greater relative flexibility of the coordination geometry for nickel(II) complexes rather than electronic differences such as the energies of the frontier orbitals.     

Two novel vanadium tellurites covalently bonded with metal-organic complex moieties: M(phen)V(2)TeO(8) (M = Cu, Ni)

Two novel two-dimensional organic-inorganic hybrid vanadium tellurites M(phen)V(2)TeO(8) (M = Cu (1), Ni (2)) have been hydrothermally synthesized and characterized by the elemental analyses, IR spectra, EPR spectrum, XPS spectra, TG analyses, and single-crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic system, space group P2(1)/c, with a = 9.2193(18) A, b = 7.9853(16) A, c = 21.401(4) A, beta = 97.54(3) degrees, and Z = 4. Compound 2 crystallizes in the monoclinic system, space group P2(1)/c, with a = 9.2163(18) A, b = 7.9897(16) A, c = 21.386(4) A, beta = 97.52(3) degrees, and Z = 4. Compounds 1 and 2 are isostructural, and both exhibit interesting two-dimensional networks with [V(2)TeO(8)]( infinity ) double-chain-like ribbons bridged by metal-organic complex moieties [M(phen)](2+) (M = Cu and Ni). Furthermore, the three-dimensional supramolecular architectures of compounds 1 and 2 are formed by pi-pi stacking interactions of phen groups between adjacent layers.     

Reactions and reactivity of Co-bpdc coordination polymers (bpdc = 4,4'-biphenyldicarboxylate)

By choosing a suitable metal center, ligand, and solvents, we have revealed several structural transformations involving a polymer precursor. infinity 1[Co(bpdc)(H2O)2].H2O (1) was prepared by reaction of Na2bpdc and Co(NO3)2 in aqueous solution. Immersing 1 in pyridine/water solutions of (2:1) and (8:1) ratios yielded a second one-dimensional structure infinity 1[Co(bpdc)(py)2(H2O)2].2py (2) and a two-dimensional structure infinity 2[Co(bpdc)(py)2].H2O (3), respectively. After heating 1 under N2 to remove all water within the structure, the compound Co(bpdc) (IR) was obtained. When IR was immersed in solutions of pyridine/water (5:4) and in pure pyridine (in air), a third one-dimensional structure of infinity 1[Co(bpdc)(py)2(H2O)2].2py.H2O (4) and 3, respectively, were obtained. Compounds 2-4 easily transformed to 1 when immersed in water. Crystal data for 1: monoclinic, space group C2/c with a = 6.950(1), b = 31.585(6), and c = 6.226(1) A, beta = 95.84(3) degrees, Z = 4. Crystal data for 2: triclinic, space group P1 with a = 9.646(2), b = 10.352(2), and c = 17.031(3) A, alpha = 79.02(3) degrees, beta = 86.88(3) degrees, gamma = 77.16(3) degrees, Z = 2. Crystal data for 3: triclinic, space group P1 with a = 9.137(2), b = 10.480(2), and c = 12.254(2) A, alpha = 102.10(3) degrees, beta = 100.80(3) degrees, gamma = 99.43(3) degrees, Z = 2. Crystal data for 4: orthorhombic, space group Pbcn with a = 13.468(3), b = 16.652 (3), and c = 14.977(3) A, Z = 4.     

Bimetallic cyanide-bridged complexes based on the photochromic nitroprusside anion and paramagnetic metal complexes. Syntheses, structures, and physical characterization of the coordination compounds [Ni(en)2]4[Fe(CN)5NO]2[Fe(CN)6]x5H2O, [Ni(en)2][Fe(CN)5NO]x3H2O, [Mn(3-MeOsalen)(H2O)]2[Fe(CN)5NO], and [Mn(5-Brsalen)]2[Fe(CN)5NO

The synthesis, crystal structure, and physical characterization of the coordination compounds [Ni(en)2]4[Fe(CN)5NO]2[Fe(CN)6]x5H2O (1), [Ni(en)2][Fe(CN)5NO]x3H2O (2), [Mn(3-MeOsalen)(H2O)]2[Fe(CN)5NO] (3), and [Mn(5-Brsalen)]2[Fe(CN)5NO] (4) are presented. 1 crystallizes in the monoclinic space group P2(1)/n (a = 7.407(4) A, b = 28.963(6) A, c = 14.744(5) A, alpha = 90 degrees, beta = 103.26(4) degrees, gamma = 90 degrees, Z = 2). Its structure consists of branched linear chains formed by cis-[Ni(en)2]2+ cations and ferrocyanide and nitroprusside anions. The presence of two kinds of iron(II) sites has been demonstrated by M?ssbauer spectroscopy. 2 crystallizes in the monoclinic space group P2(1)/c (a = 11.076(3) A, b = 10.983(2) A, c = 17.018(5) A, alpha = 90 degrees, beta = 107.25(2) degrees, gamma = 90 degrees, Z = 4). Its structure consists of zigzag chains formed by an alternated array of cis-[Ni(en)2]2+ cations and nitroprusside anions. 3 crystallizes in the triclinic space group P1 (a = 8.896(5) A, b = 10.430(5) A, c = 12.699(5) A, alpha = 71.110(5) degrees, beta = 79.990(5) degrees, gamma = 89.470(5) degrees, Z = 1). Its structure comprises neutral trinuclear bimetallic complexes in which a central [Fe(CN)5NO]2- anion is linked to two [Mn(3-MeOsalen)]+ cations. 4 crystallizes in the tetragonal space group P4/ncc (a = 13.630(5) A, c = 21.420(8) A, Z = 4). Its structure shows an extended 2D neutral network formed by cyclic octameric [-Mn-NC-Fe-CN-]4 units. The magnetic properties of these compounds indicate the presence of quasi-isolated paramagnetic Ni2+ and Mn3+. Irradiated samples of the four compounds have been studied by differential scanning calorimetry to detect the existence of the long-lived metastable states of nitroprusside.     

Synthesis and structural characterization of 0D vanadium borophosphate [Co(en)(3)](2)[V(3)P(3)BO(19)][H(2)PO(4)].4H(2)O and 1D vanadium oxides [Co(en)(3)][V(3)O(9)].H(2)O and [Co(dien)(2)][V(3)O(9)].H(2)O templated by cobalt complexes: cooperative organization of the complexes and the inorganic networks

A 0D vanadium borophosphate [Co(en)(3)](2)[V(3)P(3)BO(19)][H(2)PO(4)].4H(2)O (1) and two 1D vanadium oxides [Co(en)(3)][V(3)O(9)].H(2)O (2) and [Co(dien)(2)][V(3)O(9)].H(2)O (3) have been synthesized hydrothermally from the reaction mixture of V(2)O(5)-H(3)PO(4)-H(3)BO(3)-CoCl(2)-R-H(2)O at 110 degrees C (R: en or dien). The complex cations Co(en)(3)(3+) and Co(dien)(2)(3+) are cooperatively organized in the reaction medium to play a structure-directing role in the formation of the inorganic clusters and chains. The structures are determined by single-crystal X-ray diffraction analysis and further characterized by X-ray powder diffraction, ICP, and TG analyses. The structure of 1 contains isolated [V(3)P(3)BO(19)](5)(-) cluster anions, H(2)PO(4)(-) anions, racemic Co(en)(3)(3+) cations, and H(2)O molecules, which form a complex H-bond network. 2 and 3 both contain chains of corner-sharing VO(4) tetrahedra running along the 2(1) screw axis. The complex cations located in the interchain region interact with the chains through H-bonds. 2 is crystallized in an enantiomorphic space group and only one enantiomer of Co(en)(3)(3+) is involved in the structure. Crystal data: 1, monoclinic, C2/c, a = 32.8492(14) A, b = 11.9601(3) A, c = 22.6001(7) A, beta = 108.9630(8) degrees, Z = 8; 2, orthorhombic, P2(1)2(1)2(1), a = 8.1587(16) A, b = 12.675(3) A, c = 18.046(4) A, Z = 4; 3, monoclinic, P2(1)/c, a = 16.1663(10) A, b = 8.7028(3) A, c = 13.9773(5) A, beta = 103.1340(18) degrees, Z = 4.     

Multi-iron silicotungstates: synthesis, characterization, and stability studies of polyoxometalate dimers

The reaction of Fe(III) with Na(+) and K(+) salts of the trivacant [alpha-SiW(9)O(34)](10)(-) ligand have been investigated at pH 6 and pH 1. A new dimer, [(alpha-SiFe(3)W(9)(OH)(3)O(34))(2)(OH)(3)](11-) (1), is synthesized by reacting Na(7)H(3)[alpha-SiW(9)O(34)] or K(10)[alpha-SiW(9)O(34)] with exactly 3 equiv of Fe(III) in a 0.5 M sodium acetate solution (pH 6). The structure of 1, determined by single-crystal X-ray diffraction (a = 22.454(2) A, b = 12.387(2) A, c = 37.421(2), beta = 100.107(8) degrees , monoclinic, C2/c, Z = 4, R(1) = 5.11% based on 12739 independent reflections), consists of two [alpha-SiFe(3)W(9)(OH)(3)O(34)](4-) units linked by three Fe-mu-OH-Fe bonds. Reaction of K(10)[alpha-SiW(9)O(34)] with 3 equiv of Fe(III) in water (pH 1) yields [(alpha-Si(FeOH(2))(2)FeW(9)(OH)(3)O(34))(2)](8)(-2). The structure of 2 was also determined by single-crystal X-ray diffraction (a = 36.903(2) A, b = 13.9868(9) A, c = 21.7839(13) A, beta = 122.709(1) degrees , monoclinic, C2/c, Z = 4, R(1) = 4.57% based on 11787 independent reflections). It consists of two [alpha-Si(FeOH(2))(2)FeW(9)(OH)(3)O(34)](4-) Keggin units linked by a single edge. The terminal ligand on Fe1 in each trisubstituted Keggin unit becomes a mu(2) oxo ligand bridging to a [WO(6)](2-) moiety. The UV-vis spectra of both complexes show the characteristic oxygen-to-metal-charge-transfer bands of polyoxometalates as well as an Fe(III)-centered band at 436 nm (epsilon = 146 M(-1) cm(-1)) and 456 nm (epsilon = 104 M(-1) cm(-1)) for complexes 1 and 2, respectively. Differential scanning calorimetry data show that complex 1 decomposes between 575 and 600 degrees C whereas no decomposition is observed for complex 2 up to temperatures of 600 degrees C.     

Novel boxlike dinuclear or chain polymeric silver(I) complexes with polypyridyl bridging ligands: syntheses, crystal structures, and spectroscopic and electrochemical properties

The syntheses, characterization, crystal structures, and photophysical and electrochemical properties of two dinuclear and two polymeric Ag(I) complexes with three polypyridyl ligands, 2,3-di-2-pyridylquinoxaline (L(1)), 2,3-di-2-pyridyl-5,8-dimethoxyquinoxaline (L(2)), and 2,3,7,8-tetrakis(2-pyridyl)pyrazino[2,3-g] quinoxaline (L(3)), are described. The structures of the two boxlike dinuclear complexes with L(1) and L(2) and two chemically the same but differently crystallized one-dimensional zigzag chain coordination polymers also consisting of boxlike dinuclear subunits have been elucidated by X-ray analysis. [AgL(1)(CH(3)CN)](2)-(BF(4))(2).2CHCl(3) (1): monoclinic, C2/c; a = 28.631(2), b = 12.2259(11), c = 14.3058(12) A; beta = 99.180(2) degrees; Z = 4. [AgL(2)(CH(3)CN)(2)](2)(ClO(4))(2) (2): triclinic, P1; a = 12.3398(2), b = 13.750(2), c = 14.326(7) A; alpha = 83.494(3), beta = 74.631(3), gamma = 76.422(3) degrees; Z = 4. [[Ag(2)L(3)(NO(3))(2)].CH(3)CN](infinity) (3a): monoclinic, P2(1)/c; a = 9.5836(8), b = 13.4691(12), c = 14.0423(12) A; beta = 107.753(2) degrees; Z = 4. [Ag(2)L(3)()(NO(3))(2)](infinity) (3b): monoclinic, P2(1)/c; a = 8.4689(6), b = 16.0447(12), c = 11.7307(8) A; beta = 102.051(1) degrees; Z = 2. The structures of the dinuclear complexes 1 and 2 are similar to each other, with the two intramolecular Ag(I) centers of each complex being spanned by two ligands thus forming a unique boxlike cyclic dimer. In 1, each Ag(I) center is four-coordinated by three nitrogen atoms of two L(1) ligands and a CH(3)CN nitrogen donor, taking a distorted tetrahedral coordination geometry. The coordination environment of Ag(I) in 2 is similar to that in 1, except the formation of an additional weak coordination bond with the oxygen atom of the methoxy group of L(2). The structures of 3a,b are very similar to each other, except for the stacking patterns in the crystal lattices, and the cyclic boxlike dinuclear unit, which is similar to the structure of 1, constitutes the fundamental building block to form the one-dimensional zigzag chain structures due to the "end-on" nature of L(3). 1-3 exhibit metal-perturbed intraligand transitions in solution in 360-390 nm regions. Cyclic voltammetric studies of these complexes show the presence of reduction peak at approximately -0.5 V vs Fc(+/0). In the solid state at 77 K, they exhibit broad emission that may be assignable to originate from the metal-perturbed intraligand transitions.     

Crystal structure and spectroscopic study of novel two- and three-dimensional photoluminescent Eu(III)-adipate compounds

Two new photoluminescent compounds with the formulas of [Eu(2)(adipate)(3)(H(2)O)].H(2)O (1) and [Eu(2)(adipate)(3)(4H(2)O)] (2) were synthesized by using Eu(III) chloride and adipic acid under hydrothermal reaction conditions in aqueous solution. Compound 1, a 3-D layered framework, possesses infinite Eu-O-Eu polyhedral chains and self-assembled adipate ligands between Eu-O layers. Compound 2 has dimeric Eu(2)O(16) units interconnected by adipate ligand, resulting in 2-D open frameworks with a cavity among the ligands. Crystal data 1: monoclinic space group C2/c, with a = 14.2486(12) A, b = 8.2733(7) A, c = 39.298(2) A, beta = 99.530(6) degrees, and Z = 8. 2: monoclinic space group P2(1)/c, with a = 11.661(4) A, b = 14.011(3) A, c = 9.013(4) A, beta = 110.87(3) degrees, and Z = 2. The ligand conformations of two Eu(III)-adipate (1 and 2) compounds present anti/anti/anti, gauche/anti/gauche, and intermediate forms. Both compounds 1 and 2 showed strong red luminescence upon excitation, and their luminescence decay involves the multiphonon relaxation mechanism.     

Tetranuclear manganese carboxylate complexes with a trigonal pyramidal metal topology via controlled potential electrolysis

Controlled potential electrolysis (CPE) procedures are described that provide access to complexes with a [Mn4(mu 3-O)3(mu 3-O2CR)]6+ core (3MnIII,MnIV) and a trigonal pyramidal metal topology, starting from species containing the [Mn4(mu 3-O)2]8+ core (4MnIII). [Mn4O2(O2CMe)6(py)2(dbm)2] (6): triclinic, P1, a = 10.868(3) A, b = 13.864(3) A, c = 10.625(3) A, alpha = 108.62(1) degrees, beta = 118.98(1) degrees, gamma = 89.34(2) degrees, V = 1307 A3, Z = 1, T = -131 degrees C, R (Rw) = 3.24 (3.70)%. [Mn4O2(O2CPh)6(py)(dbm)2] (8): monoclinic, P2(1)/c, a = 14.743(6) A, b = 15.536(8) A, c = 30.006(13) A, beta = 102.79(1) degrees, V = 6702 A3, Z = 4, T = -155 degrees C, R (Rw) = 4.32 (4.44)%. Both 6 and 8 contain a [Mn4O2]8+ core; 8 only has one py group, the fourth MnIII site being five-coordinate. (NBun4)[Mn4O2(O2CPh)7(dbm)2] (10) is available from two related procedures. CPE of 10 at 0.65 V vs ferocene in MeCN leads to precipitation of [Mn4O3(O2CPh)4(dbm)3] (11); similarly, CPE of 6 at 0.84 V in MeCN/CH2Cl2 (3:1 v/v) gives [Mn4O3(O2CMe)4(dbm)3] (12). Complex 11: monoclinic, P2(1)/n, a = 15.161(3) A, b = 21.577(4) A, c = 22.683(5) A, beta = 108.04(3) degrees, V = 7056 A3, Z = 4, T = -100 degrees C, R (wR2) = 8.63 (21.80)%. Complex 12: monoclinic, P2(1)/n, a = 13.549(2) A, b = 22.338(4) A, c = 16.618(2) A, beta = 103.74(1) degrees, V = 4885 A3, Z = 4, T = -171 degrees C, R (Rw) = 4.63 (4.45)%. Both 11 and 12 contain a [Mn4(mu 3-O)3(mu-O2CR)] core with a Mn4 trigonal pyramid (MnIV at the apex) and the RCO2- bridging the MnIII3 base. However, in 11, the carboxylate is eta 2,mu 3 with one O atom terminal to one MnIII and the other O atom bridging the other two MnIII ions, whereas in 12 the carboxylate is eta 1,mu 3, a single O atom bridging three MnIII ions. Variable-temperature, solid-state magnetic susceptibility studies on 11 and 12 show that, for both complexes, there are antiferromagnetic exchange interactions between MnIII/MnIV pairs, and ferromagnetic interactions between MnIII/MnIII pairs. In both cases, the resultant ground states of the complex is S = 9/2, confirmed by magnetization vs field studies in the 2.00-30.0 K and 0.50-50 kG temperature and field ranges, respectively.     

New d0 transition metal iodates: synthesis, structure, and characterization of BaTi(IO3)6, LaTiO(IO3)5, Ba2VO2(IO3)4.(IO3), K2MoO2(IO3)4, and BaMoO2(IO3)4.H2O

Five new d0 transition metal iodates, BaTi(IO3)6, LaTiO(IO3)5, Ba2VO2(IO3)4.(IO3), K2MoO2(IO3)4, and BaMoO2(IO3)4.H2O, have been synthesized by hydrothermal methods using Ba(OH)2.8H2O, La2O3, K2CO3, TiO2, V2O5, MoO3, and HIO3 as reagents. The structures of these compounds were determined by single-crystal X-ray diffraction. All of the reported materials have zero-dimensional or pseudo-one-dimensional crystal structures composed of MO6 (M = Ti4+, V5+, or Mo6+) octahedra connected to IO3 polyhedra. Infrared and Raman spectroscopy, thermogravimetric analysis, and UV-vis diffuse reflectance spectroscopy are also presented. Crystal data: BaTi(IO3)6, trigonal, space group R-3 (No. 148), with a = b = 11.4711(10) A, c = 11.1465(17) A, V = 1270.2(2) A3, and Z = 3; LaTiO(IO3)5, monoclinic, space group P2(1)/n (No. 14), with a = 7.4798(10) A, b = 18.065(2) A, c = 10.4843(14) A, beta = 91.742(2) degrees , V = 1416.0(3) A3, and Z = 4; Ba2VO2(IO3)4.(IO3), monoclinic, space group P2(1)/c (No. 14), with a = 7.5012(9) A, b = 33.032(4) A, c = 7.2150(9) A, beta = 116.612(2) degrees , V = 1598.3(3) A3, and Z = 4; K2MoO2(IO3)4, monoclinic, space group C2/c (No. 15), with a = 12.959(2) A, b = 6.0793(9) A, c = 17.748(3) A, beta = 102.410(4) degrees , V = 1365.5(4) A3, and Z = 4; BaMoO2(IO3)4.H(2)O, monoclinic, space group P2(1)/n (No. 14), with a = 13.3368(17) A, b = 5.6846(7) A, c = 18.405(2) A, beta = 103.636(2) degrees , V = 1356.0(3) A3, and Z = 4.     

Hydrothermal syntheses, crystal structures, and magnetic properties of inorganic-organic hybrid vanadium selenites with zero- to three-dimensional structures: (1,10-phenanthroline)(2)V(2)SeO(7), (2,2'-bipyridine)VSeO(4), (4,4'-bipyridine)V(2)Se(2)O(8), and (4,4'-bipyridine)(2)V(4)Se(3)O(15).H(2)O

A family of inorganic-organic hybrid vanadium selenites with zero-, one-, two-, and three-dimensional structures, (1,10-phen)(2)V(2)SeO(7), (2,2'-bipy)VSeO(4), (4,4'-bipy)V(2)Se(2)O(8), and (4,4'-bipy)(2)V(4)Se(3)O(15).H(2)O (where phen = phenanthroline and bipy = bipyridine), were hydrothermally synthesized and characterized by single-crystal X-ray diffraction. Different bidentate organodiamine ligands and reactant concentrations were used in the four reaction systems, which are responsible for the variety of structural dimensions of the compounds. (1,10-phen)(2)V(2)SeO(7) crystallizes in a monoclinic system with space group P2(1)/n and cell parameters a = 8.6509(3) A,( )b = 7.8379(2) A, c = 34.0998(13) A, beta = 91.503(2) degrees, and Z = 4. (2,2'-bipy)VSeO(4) crystallizes in a monoclinic system with space group C2/c and cell parameters a = 17.0895(12) A, b = 14.7707(10) A, c = 11.7657(8) A, beta = 131.354(3) degrees, and Z = 8. (4,4'-bipy)V(2)Se(2)O(8) crystallizes in a triclinic system with space group Ponemacr; and cell parameters a = 7.1810(10) A, b = 10.8937(13) A, c = 11.1811(15) A, alpha = 115.455(3) degrees, beta = 107.582(3) degrees, gamma = 91.957(4) degrees, and Z = 2. (4,4'-bipy)(2)V(4)Se(3)O(15).H(2)O crystallizes in a monoclinic system with space group Pc and cell parameters a = 7.9889(9) A, b = 7.8448 A, c = 23.048(3) A, beta = 99.389(4) degrees, and Z = 2. (1,10-phen)(2)V(2)SeO(7) has an isolated structure, (2,2'-bipy)VSeO(4) has a chain structure, (4,4'-bipy)V(2)Se(2)O(8) has a layered structure, and (4,4'-bipy)(2)V(4)Se(3)O(15).H(2)O has a framework structure. The chains are constructed from VO(4)N(2) octahedra and SeO(3) pyramids, laced by organic ligands (2,2'-bipy). The layers consist of vanadium selenite chains [(VO)(2)(SeO(3))(2)]( infinity ), linked by 4,4'-bipy molecules. The framework is composed of vanadium selenite sheets [V(4)Se(3)O(16)]( infinity ), pillared by 4,4'-bipy molecules. All of the compounds are thermally stable to 300 degrees C, and the magnetic susceptibilities confirm the existence of tetravalent V atoms in the antiferromagnetic (4,4'-bipy)V(2)Se(2)O(8) complex and mixed tetravalent and pentavalent V atoms in the paramagnetic complex (4,4'-bipy)(2)V(4)Se(3)O(15).H(2)O.