The folded, tetrameric phosph(III)azane macrocycle [(P(mu-NtBu))2(1,4-(NH)2C6H4)]4

The tetrameric macrocycle [(P(mu-NtBu))2(1,4-(NH)2C6H4)]4, obtained from the reaction of the phosphazane dimer [ClP(mu-NtBu)]2 with p-phenylenediamine, has an unusual folded conformation in the solid state and contains a roughly tetrahedral arrangement of endo N-H groups for the potential coordination of anions.     

From calcium interaction to calcium electrochemical detection by [(C5H5)Fe(C5H4COCH=CHC6H4NEt2)] and its two novel structurally characterized derivatives

[(C(5)H(5))Fe(C(5)H(4)COCH=CHC(6)H(4)NEt(2))] (1) has been electrochemically evaluated toward different cations in solution. Calcium sensing by this compound and its two new derivatives [(C(5)H(5))Fe(C(5)H(4)CO(CH=CH)(2)C(6)H(4)NMe(2))] (2) and [(C(5)H(5))Fe(C(5)H(4)CH=CHCOCH=CHC(6)H(4)NEt(2))] (3) that exhibit a conjugated link between the ferrocene unit and the nitrogen atom has been thoroughly examined. Compounds 2 and 3 have been structurally characterized by single-crystal X-ray diffraction studies. The three related protonated species [1H][BF(4)] (4), [2H][BF(4)] (5), and [3H][BF(4)] (6) have been isolated in a good yield. NMR experiments clearly established that calcium interaction occurs in the vicinity of the carbonyl group, and mass spectrometry studies confirmed that this interaction, which involves several ligand-Ca(2+) adducts, is complex. A combination of electrochemical and NMR experiments highlighted an original salt influence on the electrochemical calcium sensing result.     

Reaction of [P(2)N(2)]Ta==CH(2)(Me) with ethylene: synthesis of [P(2)N(2)]Ta(C(2)H(4))Et, a neutral species with a beta-agostic ethyl group in equilibrium with an alpha-agostic ethyl group ([P(2)N(2)] = PhP(CH(2)SiMe(2)CH(2))(2)PPh).

The photolysis of [P(2)N(2)]TaMe(3) ([P(2)N(2)] = PhP(CH(2)SiMe(2)NSiMe(2)CH(2))(2)PPh) produces [P(2)N(2)]Ta=CH(2)(Me) as the major product. The thermally unstable methylidene complex decomposes in solution in the absence of trapping agents to unidentified products. However, in the presence of ethylene [P(2)N(2)]Ta=CH(2)(Me) is slowly converted to [P(2)N(2)]Ta(C(2)H(4))Et, with [P(2)N(2)]Ta(C(2)H(4))Me observed as a minor product. A mechanistic study suggests that the formation of [P(2)N(2)]Ta(C(2)H(4))Et results from the trapping of [P(2)N(2)]TaEt, formed by the migratory insertion of the methylene moiety into the tantalum-methyl bond. The minor product, [P(2)N(2)]Ta(C(2)H(4))Me, forms from the decomposition of a tantalacyclobutane resulting from the addition of ethylene to [P(2)N(2)]Ta=CH(2)(Me) and is accompanied by the production of an equivalent of propylene. Pure [P(2)N(2)]Ta(C(2)H(4))Et can be synthesized by hydrogenation of [P(2)N(2)]TaMe(3) in the presence of PMe(3), followed by the reaction of ethylene with the resulting trihydride. Crystallographic and NMR data indicate the presence of a beta-agostic interaction between the ethyl group and tantalum center in [P(2)N(2)]Ta(C(2)H(4))Et. Partially deuterated analogues of [P(2)N(2)]Ta(C(2)H(4))Et show a large isotopic perturbation of resonance for both the beta-protons and the alpha-protons of the ethyl group, indicative of an equilibrium between a beta-agostic and an alpha-agostic interaction for the ethyl group in solution. An EXSY spectrum demonstrates that an additional fluxional process occurs that exchanges all of the (1)H environments of the ethyl and ethylene ligands. The mechanism of this exchange is believed to involve the direct transfer of the beta-agostic hydrogen atom from the ethyl group to the ethylene ligand, via the so-called beta-hydrogen transfer process.     

Thermal decomposition of Pr[(C_5H_8NS_2)_3(C_(12)H_8N_2)]

The thermal behavior of the complex Pr[(C5H8NS2)3(C12H8N2)] in a dry nitrogen flow was examined by TG-DTG analysis. The TG-DTG investigations indicated that Pr[(C5H8NS2)3-(C12H8N2)] was decomposed into Pr2S3 and deposited carbon in one step where Pr2S3 predominated in the final products. The results of non-isothermal kinetic calculations showed that the decomposition stage was the random nucleation and subsequent growth mechanism (n = 2/3), the corresponding apparent activation energy ?was 115.89 kJ·mol-1 and the pre-expo-nential constant ln[A/s] was 7.8697. The empirical kinetics model equation was proposed as/(α) =3/2(1-α)[-ln(1-α)]1/3.The X-ray powder diffraction patterns of the thermal decomposition products at 800℃under N2 atmosphere show that the product can be indexed to the cubic Pr2S3 phase. The transmission electron microscopy (TEM) of the final product reveals the particle appearance of a diameter within 40 nm. The experimental results show that the praseodymium sulfide nanocrystal can be prepared from thermal decomposition of Pr[(C5H8NS2)3(C12H8N2)].     

Construction of titanasiloxanes by incorporation of silanols to the metal oxide model [(Ti(eta 5-C5Me5)(mu-O))3(mu3-CR)]: DFT elucidation of the reaction mechanism

A family of novel titanasiloxanes containing the structural unit {[Ti(eta(5)-C(5)Me(5))O](3)} were synthesized by hydron-transfer processes involving reactions with equimolecular amounts of mu(3)-alkylidyne derivatives [{Ti(eta(5)-C(5)Me(5))(mu-O)}(3)(mu(3)-CR)] (R=H (1), Me (2)) and monosilanols, R(3)'Si(OH), silanediols, R(2)'Si(OH)(2), and the silanetriol tBuSi(OH)(3). Treatment of 1 and 2 with triorganosilanols (R'=Ph, iPr) in hexane affords the new metallasiloxane derivatives [{Ti(eta(5)-C(5)Me(5))(mu-O)}(3)(mu-CHR)(OSiR(3)')] (R=H, R'=Ph (3), iPr (4); R=Me, R'=Ph (5), iPr (6)). Analogous reactions with silanediols, (R'=Ph, iPr), give the cyclic titanasiloxanes [{Ti(eta(5)-C(5)Me(5))(mu-O)}(3)(mu-O(2)SiR'(2))(R)] (R=Me, R'=Ph (7), iPr (8); R=Et, R'=Ph (9), iPr (10)). Utilization of tBuSi(OH)(3) with 1 or 2 at room temperature produces the intermediate complexes [{Ti(eta(5)-C(5)Me(5)) (mu-O)}(3)(mu-O(2)Si(OH)tBu)(R)] (R=Me (11), Et(12)). Further heating of solutions of 11 or 12 affords the same compound with an adamantanoid structure, [{Ti(eta(5)-C(5)Me(5))(mu-O)}(3)(mu-O(3)SitBu)] (13) and methane or ethane elimination, respectively. The X-ray crystal structures of 3, 4, 6, 8, 10, 12, and 13 have been determined. To gain an insight into the mechanism of these reactions, DFT calculations have been performed on the incorporation of monosilanols to the model complex [{Ti(eta(5)-C(5)H(5))(mu-O)}(3)(mu(3)-CMe)] (2 H). The proposed mechanism consists of three steps: 1) hydron transfer from the silanol to one of the oxygen atoms of the Ti(3)O(3) ring, forming a titanasiloxane; 2) intramolecular hydron migration to the alkylidyne moiety; and 3) a mu-alkylidene ligand rotation to give the final product.     

Darstellung,spektroskopische Charakterisierung und Kristallstrukturen von [(C5H5N)2CH2][PtCl5(SCN)] und cis-[(C5H5N)2CH2][PtCl4(SCN)2]

Preparation, Spectroscopic Characterization, and Crystal Structures of [(C₅H₅N)₂CH₂][PtCl₅(SCN)] and cis -[(C₅H₅N)₂CH₂][PtCl₄(SCN)₂] By treatment of [PtCl₆]^2– with SCN^– in aqueous solution a mixture of chlorothiocyanatoplatinates(IV) is formed, from which [PtCl₅(SCN)]^2– and cis-[PtCl₄(SCN)₂]^2– have been separated by ion exchange chromatography on diethylaminoethyl cellulose. X-Ray structure determinations on single crystals of [(C₅H₅N)₂CH₂][PtCl₅(SCN)] ( 1 ) (tetragonal, space group P 4₃, a = 7.687(1), c = 29.698(4), Z = 4) and cis-[(C₅H₅N)₂CH₂][PtCl₄(SCN)₂] ( 2 ) (monoclinic, space group P 2₁/n, a = 11.2467(9), b = 15.0445(10), c = 11.3179(13), β = 92.840(9)°, Z = 4) show, that the thiocyanate groups are coordinated via S atoms with average Pt–S distances of 2.339 Å and Pt–S–C angles of 104.7° up to 107.1°. Using the molecular parameters of the X-ray determinations the low temperature (10 K) IR and Raman spectra have been assigned by normal coordinate analyses. The valence force constants of the S–Pt–Cl˙ axes are f_d(PtS) = 1.81 ( 1 ) and 1.87 ( 2 ), f_d(PtCl ^× ) = 1.77 ( 1 ) and 1.81 ( 2 ), of the Cl–Pt–Cl axes are f_d(PtCl) = 1.93 ( 1 ) and 1.90 mdyn/Å ( 2 ). The ¹⁹⁵Pt NMR spectra from dichlormethane solutions exhibit each one sharp signal at 3975.6 ( 1 ) and 3231.6 ppm ( 2 ), respectively.     

Different transmetallation behaviour of [M(P4HR4)] salts toward rhodium(I) and copper(I) (M = Na, K; R = Ph, Mes; Mes = 2,4,6-Me3C6H2)

[K(2)(P(4)Mes(4))] (1) or [Na(2)(THF)(4)(P(4)Mes(4))] (2) (Mes = 2,4,6-Me(3)C(6)H(2)) reacts with one equivalent of HCl and subsequently with 0.5 equivalents of [{RhCl(cod)}(2)] (cod = 1,5-cyclooctadiene) to give a mixture of rhodium complexes, from which [Rh(P(4)HMes(4))(cod)] (3) and the secondary product [Rh(2)(micro-P(2)HMes(2))(mu-PHMes)(cod)(2)] (4) were isolated and characterised by X-ray diffraction studies. Alternatively, the reaction of [K(2)(P(4)Ph(4))] (5) or [Na(2)(THF)(5)(P(4)Ph(4))] (6) with one equivalent of HCl and subsequently with one equivalent of [CuCl(PCyp(3))(2)] (Cyp = cyclo-C(5)H(9)) gave the complex [Cu(4)(P(4)Ph(4))(2)(PH(2)Ph)(2)(PCyp(3))(2)] (7), presumably via disproportionation of the monoanion (P(4)HPh(4))(-).     

Synthesis and x-ray crystal structure of [(THF)Zn(O(2)(OH)SiR)](4) (R = (2,6-i-Pr(2)C(6)H(3))N(SiMe(3))): enroute to larger aggregates

Reaction of aminosilanetriol RSi(OH)(3) (1) (R = (2,6-i-Pr(2)C(6)H(3))N(SiMe(3))) with diethyl zinc at room temperature in 1:1 stoichiometric ratio affords [(THF)Zn(O(2)(OH)SiR)](4) (2) (R = (2,6-i-Pr(2)C(6)H(3))N(SiMe(3))) in good yield. The single-crystal X-ray diffraction studies reveal that 2 is monoclinic, P2(1), with a = 17.117(3) A, b = 16.692(5) A, c = 17.399(4) A, alpha = gamma = 90 degrees, beta = 91.45(7) degrees, and Z = 2. The molecular structure of 2 contains two puckered eight-membered Zn(2)Si(2)O(4) rings, which are connected by the Zn-O bonds and form two planar four-membered Zn(2)O(2) rings. Compound 2 contains an unreacted hydroxyl group on each silicon atom, and hence, we carried out the reactions of 2 with dimethylzinc and methyllithium to form [Zn(4)(THF)(4)(MeZn)(4)(O(3)SiR)(4)] (3) (R = (2,6-i-Pr(2)C(6)H(3))N(SiMe(3))) and [(L)ZnLi(O(3)SiR)](4) (4) (L = 1,4-(Me(2)N)(2)C(6)H(4), R = (2,6-i-Pr(2)C(6)H(3))N(SiMe(3))), respectively. This suggested that 2 could be an intermediate product formed during the synthesis of 3 and 4.     

Di- and trinuclear complexes derived from hexakis(2-pyridyloxy)cyclotriphosphazene. Unusual P-O bond cleavage in the formation of [{(L'CuCl)2(Co(NO3)}Cl] (L' = N3P3(OC5H4N)5(O))

Hexakis(2-pyridyloxy)cyclotriphosphazene (L) is an efficient multisite coordination ligand which binds with transition metal ions to produce dinuclear (homo- and heterometallic) complexes [L(CuCl)(CoCl3)], [L(CuCl)(ZnCl3)], [L(CoCl)(ZnCl3)], and [L(ZnCl2)2]. In these dinuclear derivatives the cyclophosphazene ligand utilizes from five to six nitrogen coordination sites out of the maximum of nine available sites. Further, the spacer oxygen that separates the pyridyl moiety from the cyclophosphazene ring ensures minimum steric strain to the cyclophosphazene ring upon coordination. This is reflected in the near planarity of the cyclophosphazene ring in all the dinuclear derivatives. In the dinuclear heterobimetallic derivatives one of the metal ions [Cu(II) or Co(II)] is hexacoordinate and is bound by the cyclophosphazene in a eta5-gem-N5 mode. The other metal ion in these heterobimetallic derivatives [Co(II) or Zn(II)] is tetracoordinate and is bound in an eta(1)-N(1) fashion. In the homobimetallic derivative, [L(ZnCl2)2], one of the zinc ions is five-coordinate (eta3-nongem-N3), while the other zinc ion is tetracoordinate(eta2-gem-N2). The reaction of L with CuCl2 followed by Co(NO3)2.6H2O yields a trinuclear heterobimetallic complex [{(L'CuCl)2Co(NO3)}Cl] [L' = N3P3(OC5H4N)5(O)]. In the formation of this compound an unusual P-O bond cleavage involving one of the phosphorus-pyridyloxy bonds is observed. The molecular structure of [{(L'CuCl)2Co(NO3)}Cl] [L' = N3P3(OC5H4N)5(O)] reveals that each of the two the P-O-cleaved L' ligands is involved in binding to Cu(II) to generate the motif L'CuCl. Two such units are bridged by a Co(II) ion. The coordination environment around the bridging Co(II) ion contains four oxygen (two P-O units, one chelating nitrate) and two nitrogen atoms (pyridyloxy nitrogens).     

A New Heteropolyoxotungstate with a Three-dimensional All-inorganic Framework [（C2H4N2）4（P4Co3W4O（28）H6）（H2C2O4）]n

A new heteropolyoxotungstate [(C2H4N2)4(P4Co3W4O28H6)(H2C2O4)]n with a three-dimensional framework was hydrothermally synthesized.The compound crystallizes in a tetragonal system,space group I41/a with a = 17.1006(17),b = 17.1006(7),c = 10.7525(5),V = 3144.2(2)3,Z = 4,Dc = 3.795 g·cm-3,F(000) = 3300,MoKα(λ = 0.71073 ),μ = 16.460 mm-1,the final R = 0.0335 and wR = 0.0776.In the heteropolyoxotungstate,tungsten-oxygen octahedra are linked by sharing two cis-vertexes into an infinite helical chain extending along the c axis.Cobalt atoms in the octahedral geometry act as the linkers of these chains,forming a three-dimensional framework.The cobalt and phosphorus atoms in the tetrahedral geometry play a role in stabilizing the three-dimensional framework.Ethylenediamine molecules are polymerized into organic chains which locate in the interspaces of the framework in the way of interwinding with the W-O chains.     

Low temperature in situ UV irradiation of [(eta 5-C5H5)Co(C2H4)2] in the NMR probe: formation of Co(III) silyl hydride complexes

Low temperature in situ UV irradiation of [(eta(5)-C(5)H(5))Co(C(2)H(4))(2)] in the presence of silanes enables the characterisation of unstable fluxional Co(III) silyl hydride complexes [(eta(5)-C(5)H(5))Co(SiR(3))(H)(C(2)H(4))] (SiR(3) = SiEt(3), SiMe(3) or SiHEt(2)) by NMR spectroscopy; the reaction of [Co(eta(5)-C(5)H(5))(C(2)H(4))(2)] with HSiR(3) proceeds thermally to reach an equilibrium when SiR(3) = Si(OMe)(3) or SiClMePh.     

Transfer hydrogenation processes to mu(3)-alkylidyne groups on the organotitanium oxide [Ti(3)Cp*O(3)

The photochemical treatment of mu(3)-alkylidyne complexes [[TiCp*(mu-O)](3)(mu(3)-CR)] (R=H (1), Me (2), Cp*=eta(5)-C(5)Me(5)) with the amines (2,6-Me(2)C(6)H(3))NH(2), Et(2)NH, and Ph(2)NH and the imine Ph(2)C=NH leads to the partial hydrogenation of the alkylidyne moiety that is supported on the organometallic oxide, [Ti(3)Cp*O(3)], and the formation of new oxoderivatives [[TiCp*(3)(mu-CHR)(R'NR")] (R"=2,6-Me(2)C(6)H(3), R'=H, R=H (3), Me (4); R'=R"=Et, R=H (5), Me (6); R'=R"=Ph, R=H (7), Me (8)) and [[TiCp*(mu-O)](3)(mu-CHR)(N=CPh(2))] (R=H (9), R=Me (10)), respectively. A sequential transfer hydrogenation process occurs when complex 1 is treated with tBuNH(2), which initially gives the mu-methylene [[TiCp*(mu-O)](3)(mu-CH(2))(HNtBu)] (11) complex and finally, the alkyl derivative [[TiCp*(mu-O)](3)(mu-NtBu)Me] (12). Furthermore, irradiation of solutions of the mu(3)-alkylidyne complexes 1 or 2 in the presence of diamines o-C(6)H(4)(NH(2))(2) and H(2)NCH(2)CH(2)NH(2) (en) affords [[TiCp*(mu-O)](3)(mu(3)-eta(2)-NC(6)H(4)NH)] (13) and [[TiCp*(mu-O)](3)(mu(3)-eta(2)-NC(2)H(4)NH)] (14) by either methane or ethane elimination, respectively. In the reaction of 1 with en, an intermediate complex [[TiCp*(mu-O)](3)(mu-CH(2))(NHCH(2)CH(2)NH(2))] (15) is detected by (1)H NMR spectroscopy. Thermal treatment of the complexes 4-10 quantitatively regenerates the starting mu(3)-alkylidyne compounds and the amine R'(2)NH or the imine Ph(2)C=NH; however, heating of solutions of 3 or 4 in [D(6)]benzene or a equimolecular mixture of both at 170 degrees C produces methane, ethane, or both, and the complex [[TiCp*(mu-O)](3)[mu(3)-eta(2)-NC(6)H(3)(Me)CH(2)]] (16). The molecular structure of 8 has been established by single-crystal X-ray analysis.     

Alkylation reactions of [WS(4)](2)(-) and [(eta(5)-C(5)Me(5))WS(3)](-) with 2,6-bis(bromomethyl)pyridine: the first isolation of bisalkylated tetrathiometalate WS(2)[2,6-(SCH(2))(2)(C(5)H(3)N)

The trithio and tetrathio complexes of tungsten (PPh(4))[CpWS(3)] (Cp = eta(5)-C(5)Me(5)) and (PPh(4))(2)[WS(4)] undergo alkylation reactions with 2,6-bis(bromomethyl)pyridine to yield [(CpWS(2))(2)[2,6-(SCH(2))(2)(C(5)H(3)N)]].CH(3)CN (1.CH3CN) (73.1% yield) and WS(2)[2,6-(SCH(2))(2)(C(5)H(3)N)] (2) (76.0% yield), respectively. In the dinuclear complex 1, two CpWS(3) units are linked by a 2,6-dimethylenepyridine bridge, and the pyridine nitrogen is not coordinated at tungsten. Complex 2 is the first example of bisalkylated tetrathiometalates, the mononuclear structure of which is stabilized by coordination of the pyridine nitrogen.     

Magnetic properties of diruthenium(II,III) carboxylate compounds. Crystal structures of Ru2Cl(mu-O2CCH=CHCH=CHMe)4 and Ru2Cl(mu-O2CCH2OMe)4

The reaction of Ru2Cl(mu-O2CMe)4 with 2,4-hexadienoic and 2-methoxyacetic acids affords the compounds Ru2Cl(mu-O2CR)4 [R = CH=CHCH=CHCH3 (1), CH2OMe (2)]. The structures of both complexes have been determined by X-ray crystallography. 1 crystallizes in the triclinic space group P-1 with a = 9.264(1) A, b = 12.661(8) A, c = 12.839(5) A, alpha = 106.09(3) degrees, beta = 77.89(2) degrees, gamma = 97.73(3) degrees, and Z = 2. 2 crystallizes in the nonstandard monoclinic space group P2(1)/c with a = 12.132(4) A, b = 11.570(2) A, c = 13.674(2) A, beta = 91.18(2) degrees, and Z = 4. Complexes 1 and 2 show [Ru2(mu-O2CR)4]+ units linked by chloride ions, giving zigzag chains with Ru-Cl-Ru angles of 119.43(4) degrees and 110.11(7) degrees, respectively. The Ru-Ru bond distances are 2.2857(9) A (1) and 2.290(1) A (2). A magnetic study, in the 2-300 K temperature range, of the new compounds and the previously described Ru2Cl(mu-O2CR)4 [R = CHMe2 (3), CMe3 (4), C4H4N (5)] is described. The polymeric complexes 1 and 2 and the nonpolymeric 3-5 show a large zero-field splitting which varies from 53.9 to 68.1 cm-1. These complexes also show a weak, but not negligible, through-space intermolecular antiferromagnetic coupling not observed in the previous magnetic studies carried out on these types of compounds.     

Trans --> cis isomerization of trans-[(dppm)2Ru(H)(L)][BF4] (L = P(OR)3) complexes: preparation of cis-[(dppm)2Ru(eta2-H2)(L)][BF4]2

A series of new dicationic dihydrogen complexes of ruthenium of the type cis-[(dppm)(2)Ru(eta(2)-H(2))(L)][BF(4)](2) (dppm = Ph(2)PCH(2)PPh(2); L = P(OMe)(3), P(OEt)(3), PF(O(i)Pr)(2)) have been prepared by protonating the precursor hydride complexes cis-[(dppm)(2)Ru(H)(L)][BF(4)] (L = P(OMe)(3), P(OEt)(3), P(O(i)Pr)(3)) using HBF(4).Et(2)O. The cis-[(dppm)(2)Ru(H)(L)][BF(4)] complexes were obtained from the trans hydrides via an isomerization reaction that is acid-accelerated. This isomerization reaction gives mixtures of cis and trans hydride complexes, the ratios of which depend on the cone angles of the phosphite ligands: the greater the cone angle, the greater is the amount of the cis isomer. The eta(2)-H(2) ligand in the dihydrogen complexes is labile, and the loss of H(2) was found to be reversible. The protonation reactions of the starting hydrides with trans PMe(3) or PMe(2)Ph yield mixtures of the cis and the trans hydride complexes; further addition of the acid, however, give trans-[(dppm)(2)Ru(BF(4))Cl]. The roles of the bite angles of the dppm ligand as well as the steric and the electronic properties of the monodentate phosphorus ligands in this series of complexes are discussed. X-ray crystal structures of trans-[(dppm)(2)Ru(H)(P(OMe)(3))][BF(4)], cis-[(dppm)(2)Ru(H)(P(OMe)(3))][BF(4)], and cis-[(dppm)(2)Ru(H)(P(O(i)Pr)(3))][BF(4)] complexes have been determined.     

Synthesis and Characterization of [(C5H4SiMe2tBu)2Ln((-SnBu)]2 (Ln = Y, Er)1

(C5H4SiMe2tBu)2LnnBu reacted with 1 equiv. of elemental sulfur in toluene at ambient temperature to yield the corresponding lanthanocene thiolates [(C5H4SiMe2tBu)2Ln(m-SnBu)]2 (Ln = Y (1), Er (2)). Complexes 1 and 2 have been characterized by elemental analysis, IR, mass spectros- copy and X-ray single-crystal diffraction analysis. Both complexes are of monoclinic with space group P21/c, formula C52H94S2Si4Y2 1 (C52H94S2Si4Er2 2) Mr = 1073.57 (1230.27), a = 8.495(2) (8.41(2)), b = 26.913(8) (26.67(7)), c = 13.756(4) (13.68(4)) (A), α = 90(90), β = 101.184(5) (101.57(4)), γ = 90 (90)°, V = 3085.1(15) (3007(14))(A)3, Dc = 1.156 (1.359) g·cm-3, Z = 2 (2), F(000) = 1144 (1260), μ = 2.046 (2.951) cm-1, R = 0.0687 (0.0749) and wR = 0.1306 (0.1507) for observed reflections with I > 2σ(I). X-ray structures of 1 and 2 definitively prove that only one sulfur atom is inserted into the Ln-C(nBu) bond, forming a thiolate ligand.     

Substituted N-picolylethylenediamines of the type (ArNHCH2CH2){(2-C5H4N)CH2}NR [R = Me, 4-CH2=CH(C6H4)CH2, (2-C5H4N)CH2] and their transition metal(II) halide complexes

Alkylation of (ArNHCH2CH2){(2-C5H4N)CH2}NH with RX [RX = MeI, 4-CH2=CH(C6H4)CH2Cl) and (2-C5H5N)CH2Cl] in the presence of base has allowed access to the sterically demanding multidentate nitrogen donor ligands, {(2,4,6-Me3C6H2)NHCH2CH2}{(2-C5H4N)CH2}NMe (L1), {(2,6-Me3C6H3)NHCH2CH2}{(2-C5H4N)CH2}NCH2(C6H4)-4-CH=CH2 (L2) and (ArNHCH2CH2){(2-C5H4N)CH2}2N (Ar = 2,4-Me2C6H3 L3a, 2,6-Me2C6H3 L3b) in moderate yield. L3 can also be prepared in higher yield by the reaction of (NH2CH2CH2){(2-C5H4N)CH2}2N with the corresponding aryl bromide in the presence of base and a palladium(0) catalyst. Treatment of L1 or L2 with MCl2 [MCl2 = CoCl2.6H2O or FeCl2(THF)1.5] in THF affords the high spin complexes [(L1)MCl2](M = Co 1a, Fe 1b) and [(L2)MCl2](M = Co 2a, Fe 2b) in good yield, respectively; the molecular structure of reveals a five-coordinate metal centre with bound in a facial fashion. The six-coordinate complexes, [(L3a)MCl2](M = Co 3a, Fe 3b, Mn 3c) are accessible on treatment of tripodal L3a with MCl2. In contrast, the reaction with the more sterically encumbered leads to the pseudo-five-coordinate species [(L3b)MCl2](M = Co 4a, Fe 4b) and, in the case of manganese, dimeric [(L3b)MnCl(mu-Cl)]2 (4c); in 4a and 4b the aryl-substituted amine arm forms a partial interaction with the metal centre while in 4c the arm is pendant. The single crystal X-ray structures of , 1a, 3b.MeCN, 3c.MeCN, 4b.MeCN and 4c are described as are the solution state properties of 3b and 4b.     

Mechanistic studies of the oxidative N-dealkylation of a substrate tethered to carboxylate-bridged diiron(II) complexes, [Fe2(mu-O2CAr(Tol))2(O2CAr(Tol))2(N,N-Bn2en)2

Carboxylate-bridged diiron(II) centers activate dioxygen for the selective oxidation of hydrocarbon substrates in bacterial multicomponent monooxygenases. Synthetic analogues of these systems exist in which substrate fragments tethered to the diiron(II) core through attachment to an N-donor ligand are oxidized by transient species that arise following the introduction of O2 into the system. The present study describes the results of experiments designed to probe mechanistic details of these oxidative N-dealkylation reactions. A series of diiron(II) complexes with ligands N,N-(4-R-Bn)Bnen, where en is ethylenediamine, Bn is benzyl, and R-Bn is benzyl with a para-directing group R = Cl, F, CH3, t-Bu, or OCH3, were prepared. A Hammett plot of the oxygenation product distributions of these complexes, determined by gas chromatographic analysis, reveals a small positive slope of rho = +0.48. Kinetic isotope effect (KIE(intra)) values for oxygenation of [Fe2(mu-O2CAr(Tol))2(O2CAr(Tol))2(N,N-(C6H5CDH)2en)2] and [Fe2(mu-O2CAr(Tol))2(O2CAr(Tol))2(N,N-(C6H5CD2)(C6H5CH2)en)2] are 1.3(1) and 2.2(2) at 23 degrees C, respectively. The positive slope rho and low KIE(intra) values are consistent with a mechanism involving one-electron transfer from the dangling nitrogen atom in N,N-Bn2en to a transient electrophilic diiron intermediate, followed by proton transfer and rearrangement to eliminate benzaldehyde.     

Synthesis and characterization of bis[bis(pentafluoroethyl)phosphinyl]imides, M(+)N[(C2F5)2P(O)]2(-), M = H, Na, K, Cs, Ag, Me4N

A convenient synthesis and a full characterization of the strong acid bis[bis(pentafluoroethyl)phosphinyl]imide and some of its salts M (+)N[(C 2F 5) 2P(O)] 2 (-), M = Na, K, Cs, Ag, Me 4N, are presented. Their thermal (mp, T dec.) and spectroscopic (IR, Raman, NMR) properties are discussed. A single crystal structure of [Me 4N][N{P(O)(C 2F 5) 2} 2] has been obtained, and the structural parameters of the anion are compared with the results of quantum-chemical calculations. The observed properties are comparable to those of bis((trifluoromethyl)sulfonyl)imide and their derivatives.     

Reactions of Elemental Indium and Indium(I) Bromide with Nickel-Bromine Bonds: Structure of (eta(5)-C(5)H(5))(Ph(3)P)Ni-InBr(2)(O=PPh(3))

The reactions of elemental indium and In(I)Br with the carbonyl-free organonickel complexes (eta(5)-C(5)H(5))(PR(3))Ni-Br (R = CH(3), C(6)H(5)) have been studied in some detail. Either redox reactions to yield the ionic products [(eta(5)-C(5)H(5))(PR(3))(2)Ni][InBr(4)] (2a,b) occurred or the Ni-In bound systems (eta(5)-C(5)H(5))(PPh(3))Ni-InBr(2)(OPPh(3)) (3a) and [(eta(5)-C(5)H(5))(PPh(3))Ni](2)InBr (4) were obtained in good yields. The new compounds were characterized by elemental analysis, NMR, and mass spectrometry. A short Ni-In bond of 244.65(9) pm was found for 3a. Single crystal data for (eta(5)-C(5)H(5))(PPh(3))Ni-InBr(2)(OPPh(3)).THF (3a): triclinic, P1 with a = 1124.9(3), b = 1353.2(4), c = 1476.4(4) pm, alpha = 94.74(2) degrees, beta = 101.78(2) degrees, gamma = 109.64(1) degrees, V = 2044(1) x 10(6) pm(3), Z = 2, R = 0.053 (R(w) = 0.063).