Rational design of 0D, 1D, and 3D open frameworks based on tetranuclear lanthanide(III) sulfonate-phosphonate clusters

Hydrothermal reactions of lanthanide(III) salts with m-sulfophenylphosphonic acid (H3L1) and 1,10-phenanthroline (phen) or N,N'-piperazinebis(methylenephosphonic acid) (H4L2) afforded six novel lanthanide(III) sulfonate-phosphonates based on tetranuclear clusters, namely, [La(2)(L1)2(phen)4(H2O)].4.5H2O (1), [Ln2(L1)2(phen)2(H2O)5].3H2O (Ln = Nd, 2; Eu, 3; Er, 4), and [Ln2(HL1)(H2L2)2(H2O)4].8H2O (Ln = La, 5; Nd, 6). Compounds 2-4 contain discrete tetranuclear lanthanide(III) cluster units in which four lanthanide(III) ions are bridged by two tridentate and two tetradentate phosphonate groups. In compound 1, the tetranuclear clusters are further interconnected into a 1D chain through the coordination of the sulfonate groups. The structures of compounds 5 and 6 can be viewed as a 3D architecture based on a different types of tetranuclear cluster units that are interconnected by bridging H2L2 anions. In the tetranuclear clusters of compounds 5 and 6, the four lanthanide(III) centers are interconnected by only two HL1 ligands. Compound 2 is a luminescent material in the near-IR region, whereas compound 3 displays a strong luminescent emission band in the red-light region. Magnetic property measurements of compounds 2-4 and 6 indicate that there are strong antiferromagetic interactions between magnetic centers within the cluster units.     

Hydrothermal synthesis, structures, and photoluminescent properties of benzenepentacarboxylate bridged networks incorporating zinc(II)-hydroxide clusters or zinc(II)-carboxylate layers

The first coordination compounds of partially or wholly deprotonated benzenepentacarboxylic acid (H5L) were synthesized in the presence or absence of auxiliary 2,2'-bipyridyl (2,2'-bpy) and 1,10-phenanthroline (phen) ligands, and their crystal structures and photoluminescent properties were characterized. Their formulas are [Zn6(mu3-OH)2(L)2(H2O)6]n (1), [Zn5(mu3-OH)2(HL)2(2,2'-bpy)2]n (2), [Zn2(HL)(phen)2(H2O)2]n (3), and [Zn5(L)2(phen)4(H2O)3]n.2nH2O (4). Both 1 and 2 are three-dimensional (3D) zinc(II)-hydroxide cluster based coordination frameworks. 1 contains distorted chairlike hexanuclear Zn6(mu3-OH)2 cluster units as secondary building blocks. Each Zn6(mu3-OH)2 unit connects six others through the three-connected nodes of L5- ligands into a 3D rigid and condensed coordination network, whereas in 2, each pentanuclear Zn5(mu3-OH)2 unit connects the other six ones through the three-connected [HL]4- nodes into a 3D network in the simple cubic packing mode. 3 has two-dimensional (2D) Zn(II)-carboxylate supramolecular layers constructed from a one-dimensional (1D) coordination chain structure by hydrogen bonds of the water and mu5-[HL]4- bridges, whereas 4 has 2D coordination layers composed of Zn(II) and mu8-L5- bridges. The adjacent coordination assemblies in 3 and 4 are further extended by hydrogen bonds and pi...pi interactions into 3D supramolecular architectures. 1-4 are photoluminescent active materials, and their photofluorescent properties are closely related to their intrinsic structure arrangements.     

Three novel zinc(II) sulfonate-phosphonates with tetranuclear or hexanuclear cluster units

Hydrothermal reactions of zinc(II) carbonate with m-sulfophenylphosphonic acid (m-HO3S-Ph-PO3H2) and 1,10-phenanthroline (phen) or 4,4'-bipyridine (bipy) lead to three novel zinc(II) sulfonate-phosphonates, namely, [Zn(phen)3]2[Zn4(m-O3S-Ph-PO3)4(phen)4].20H2O (1), [Zn6(m-O3S-Ph-PO3)4(phen)8].11H2O (2), and [Zn6(m-O3S-Ph-PO3)4(bipy)6(H2O)4].18H2O (3). Compound 1 contains a tetranuclear zinc(II) cluster anion in which four Zn(II) ions are bridged by two tetradentate and two bidentate phosphonate groups, and the four negative charges of the cluster are compensated by two [Zn(phen)3]2+ cations. Compound 2 features a hexanuclear zinc(II) cluster in which the same tetranuclear cluster of 1 is bridged with two additional Zn(II) ions. The structure of 3 features a porous 3D network based on hexanuclear zinc(II) units of [Zn6(m-O3S-Ph-PO3)4] interconnected by 4,4'-bipy ligands. The hexanuclear cluster in 3 is different from that in 2 in that all four phosphonate groups in 3 are tridentate bridging. Compounds 1, 2, and 3 exhibit broad blue fluorescent emission bands at 378, 409, and 381 nm, respectively.     

Tetranuclear clusters containing a CrIII-doped MnIII4O2 core: syntheses, structures, and magnetic properties

The oxidation of MnII carboxylates by (NBu4)Cr2O7 in the presence of different phosphonic acids and chelating ligands results in six CrIII-doped tetranuclear manganese clusters formulated [Mn3CrO2(O2CCH3)4(O3PC5H4N)2(bpy)2] (1), [Mn3CrO2(O2CCH3)4(O3PC5H4N)2(phen)2] (2), [Mn3CrO2(O2CPh)4(O3PC5H4NO)2(phen)2] (3), [Mn3CrO2(O2CPh)4(O3PC6H11)2(bpy)2] (4), [Mn 3CrO2(O2CPh)4(O3PC6H11)2(phen) 2] (5), and [Mn3CrO2(O2CCH3)4(O3PC6H11)2(bpy)2] (6). Single-crystal X-ray analyses reveal that all the compounds contain similar [M4O2]8+ cores with the four metal sites arranged in planar topologies. The metal ions within the core are bridged by both carboxylate and phosphonate ligands. Temperature-dependent magnetic measurements show that in all cases dominant antiferromagnetic interactions are propagated between the metal centers. The ac magnetic measurements on compounds 5 and 6 reveal that both the in-phase and the out-of-phase signals are frequency dependent, characteristic of single-molecule magnet behaviors.     

Assembly of azido- or cyano-bridged binuclear complexes containing the bulky [Mn(phen)2]2+ building block: syntheses, crystal structures, and magnetic properties

Two new cyano-bridged heterobinuclear complexes, [Mn(II)(phen)2Cl][Fe(III)(bpb)(CN)2] x 0.5CH3CH2OH x 1.5H2O (1) and [Mn(II)(phen)2Cl][Cr(III)(bpb)(CN)2] x 2H2O (2) [phen = 1,10-phenanthroline; bpb(2-) = 1,2-bis(pyridine-2-carboxamido)benzenate], and four novel azido-bridged Mn(II) dimeric complexes, [Mn2(phen)4(mu(1,1)-N3)2][M(III)(bpb)(CN)2]2 x H2O [M = Fe (3), Cr (4), Co (5)] and [Mn2(phen)4(mu(1,3)-N3)(N3)2]BPh4 x 0.5H2O (6), have been synthesized and characterized by single-crystal X-ray diffraction analysis and magnetic studies. Complexes 1 and 2 comprise [Mn(phen)2Cl]+ and [M(bpb)(CN)2]- units connected by one cyano ligand of [M(bpb)(CN)2]-. Complexes 3-5 are doubly end-on (EO) azido-bridged Mn(II) binuclear complexes with two [M(bpb)(CN)2]- molecules acting as charge-compensating anions. However, the Mn(II) ions in complex 6 are linked by a single end-to-end (EE) azido bridging ligand with one large free BPh4(-) group as the charge-balancing anion. The magnetic coupling between Mn(II) and Fe(III) or Cr(III) in complexes 1 and 2 was found to be antiferromagnetic with J(MnFe) = -2.68(3) cm(-1) and J(MnCr) = -4.55(1) cm(-1) on the basis of the Hamiltonian H = -JS(Mn)S(M) (M = Fe or Cr). The magnetic interactions between two Mn(II) ions in 3-5 are ferromagnetic in nature with the magnetic coupling constants of 1.15(3), 1.05(2), and 1.27(2) cm(-1) (H = -JS(Mn1)S(Mn2)), respectively. The single EE azido-bridged dimeric complex 6 manifests antiferromagnetic interaction with J = -2.29(4) cm(-1) (H = -JS(Mn1)S(Mn2)). Magneto-structural correlationship on the EO azido-bridged Mn(II) dimers has been investigated.     

Carboxylate-Free Manganese(II) Phosphonate Assemblies: Synthesis, Structure, and Magnetism

The reaction of manganese(II) salts with organophosphonic acid [t-BuPO(3)H(2) or cyclopentyl phosphonic acid (C(5)H(9)PO(3)H(2))] in the presence of ancillary nitrogen ligands [1,10-phenanthroline (phen) or 2,6-bis(pyrazol-3-yl)pyridine (dpzpy)], afforded, depending on the stoichiometry of the reactants and the reaction conditions, dinuclear, trinuclear, and tetranuclear compounds, [Mn(2)(t-BuPO(3)H)(4)(phen)(2)]·2DMF (1), [Mn(3)(C(5)H(9)PO(3))(2)(phen)(6)](ClO(4))(2)·7CH(3)OH (2), [Mn(3)(t-BuPO(3))(2)(dpzpy)(3)](ClO(4))(2)·H(2)O (3), [Mn(4)(t-BuPO(3))(2)(t-BuPO(3)H)(2)(phen)(6)(H(2)O)(2)](ClO(4))(2) (4), and [Mn(4)(C(5)H(9)PO(3))(2)(phen)(8)(H(2)O)(2)](ClO(4))(4) (5). Magnetic studies on 1, 2, and 4 reveal that the phosphonate bridges mediate weak antiferromagnetic interactions between the Mn(II) ions have also been carried out.     

Mixed-valence tetra- and hexanuclear manganese complexes from the flexibility of pyridine-containing beta-diketone ligands

The reactions of [Mn3O(O2CCCl3)6(H2O)3] with 1-phenyl-3-(2-pyridyl)propane-1,3-dione (HL(1)) and 1-(2-pyridly)-3-(p-tolyl)propane-1,3-dione (HL(2)) in CH2Cl2 afford the mixed-valence Mn(II)2Mn(III)2 tetranuclear complexes [Mn4O(O2CCCl3)6(L(1))2] (1) and [Mn4O(O2CCCl3)6L2(2)] (2), respectively. Similar reactions employing [Mn3O(O2CPh)6(H2O)(py)2] with HL(1) and HL(2) give the Mn(II)3Mn(III)3 hexanuclear complexes [Mn6O2(O2CPh)8(L(1))3] (3) and [Mn6O2(O2CPh)8L3(2)] (4), respectively. Complexes 1.2CH2Cl2, 2.2CH2Cl2.H2O, 3.1.5CH2Cl2.Et2O.H2O, and 4.2CH2Cl2 crystallize in the triclinic space group P1, monoclinic space group P2(1)/c, monoclinic space group P2 1/ n, and monoclinic space group P2(1)/n, respectively. Complexes 1 and 2 consist of a trapped-valence tetranuclear core of [Mn(II)2Mn(III)2(mu4-O)](8+), and complexes 3 and 4 represent a new structural type, possessing a [Mn(II)3Mn(III)3(mu4-O)2](11+) core. The magnetic data indicate that complexes 3 and 4 have a ground-state spin value of S = 7/2 with significant magnetoanisotropy as gauged by the D values of -0.51 cm (-1) and -0.46 cm (-1), respectively, and frequency-dependent out-of-phase signals in alternating current magnetic susceptibility studies indicate their superparamagnetic behavior. In contrast, complexes 1 and 2 are low-spin molecules with an S = 1 ground state. Single-molecule magnetism behavior confirmed for 3 the presence of sweep-rate and temperature-dependent hysteresis loops in single-crystal M versus H studies at temperatures down to 40 mK.     

Synthesis, crystal structure, and magnetic properties of hexanuclear [{MnL2}4{Nb(CN)8}2] and Nonanuclear [{MnL2}6{Nb(CN)8}3] heterometallic clusters (L=bpy, phen)

A hexanuclear cyano-bridged {MnII4NbIV2} cluster (1) bearing 2,2'-bipyridine (bpy) as the blocking ligand at manganese is obtained from the reaction of cis-[MnCl2(bpy)2] and K4[Nb(CN)8]. When the blocking ligand is 1,10-phenanthroline (phen), a nonanuclear cluster {MnII6NbIV3} (2) is obtained. The structure of [{Mn(bpy)2}4{Nb(CN)8}2] has been solved by single-crystal X-ray crystallography, whereas the phen derivative has been confirmed by means of the structure analysis of the corresponding WIV analogue [{Mn(phen)2}6{W(CN)8}3(H2O)2]. Magnetic measurements revealed S=9 and 27/2 spin ground states for these aggregates as a result of antiferromagnetic Nb-Mn interaction with JNb-Mn=-18.1 cm(-1) (1) and -13.6 cm(-1) (2).     

Mononuclear, dinuclear, hexanuclear, and one-dimensional polymeric silver complexes having ligand-supported and unsupported argentophilic interactions stabilized by pincer-like 2,6-bis(5-pyrazolyl)pyridine ligands

The mononuclear complexes [Ag(H2L1)(Py)2](NO3) x H2O (1, H2L1 = 2,6-bis(5-methyl-1H-pyrazol-3-yl)pyridine) and [Ag(NO3)(L()] (2, L2 = 2,6-bis(5-methyl-1-isopropyl-1H-pyrazol-3-yl)pyridine), dinuclear complex [Ag2(H2L3)2(HL4)2] (3, H2L3 = 2,6-bis(5-phenyl-1H-pyrazol-3-yl)pyridine, HL4 = 6-(5-phenyl-1H-pyrazolyl-3-yl)picolinate), one-dimensional polymer {[Ag2(H2L1)2](NO3)2 x H2O}(n) (4), and hexanuclear clusters [Ag6(HL1)4](X)2 (X = NO3-, 5 ; BF4-, 6 ; ClO4-, 7) stabilized by pincer-like bispyrazolyl ligands have been prepared and characterized using (1)H NMR spectroscopy, elemental analysis, IR spectroscopy, luminescence spectroscopy and X-ray diffraction. In complex , there is a ligand unsupported Ag-Ag bond between the two silver atoms. Complex displays a one-dimensional polymer consisting of an infinite Ag-Ag chain and every two adjacent silver ions are bridged by an H2L1 ligand. Complexes and have the same Ag6 cores in which six silver atoms are held together by four HL1 and five Ag-Ag bonds, while complex was held together by six Ag-Ag bonds. The silver-silver distances in these complexes are found in the range of 2.874(1)-3.333(2) A for ligand supported, and 3.040(1) A for ligand unsupported Ag-Ag bonds, respectively. Complexes 3-7 are strongly luminescent due to either intraligand or metal-ligand charge transfer processes.     

Hydrothermal synthesis, structural chemistry, and magnetic properties of materials of the MII/triazolate/anion family, where MII = Mn, Fe, and Ni

Hydrothermal chemistry has been exploited in the preparation of a series of manganese(II), iron(II), and nickel(II) triazolate frameworks, [Mn7(trz)8(CH3CO2)4(OH)2].2.5H2O (1.2.5H2O), [Mn5(Htrz)2(SO4)4(OH)2] (2), [Fe5(Htrz)2(SO4)4(OH)2] (3), [Fe3(Htrz)3(HSO4)(SO4)2(OH)].H2O (4.H2O), [Ni3(trz)3(OH)3(H2O)4].5H2O (5.5H2O), and [Ni3(trz)5(OH)].2.5H2O (6.2.5H2O). The materials all exhibit three-dimensional structures, reflecting the tendency of triazole/triazolate ligands to bridge multiple metal sites. A prominent characteristic of the structures is the presence of embedded metal clusters as building blocks: heptanuclear MnII units in 1, pentanuclear MII sites in 2 and 3, and trinuclear MII clusters in 4 and 5. The presence of the pentanuclear and trinuclear clusters of magnetic metal cations in 2-5 is reflected in the unusual magnetic characteristics of these materials, all of which exhibit spin frustration. The compound 5.5H2O reversibly desorbs/sorbs solvent. However, the dehydrated phase does not adsorb methanol, N2, O2, or H2, presumably as a consequence of the highly polar void volume and the narrow channels connecting the larger cavities of the void structure.     

铜(II)-锰(II)四核配合物的合成、晶体结构和磁性

(中国地质大学地质实验室, 北京100083) 报道了一个草酰胺桥连的四核Cu(II)Mn(II)配合物[Mn(CuL)3][Mn(H2O)6][N(CN)2]2(ClO4)2 4H2O (L为1,4,8,11-四氮杂环十四烷-2,3-二酮) (C34H74Cl2Cu3Mn2N18O24, Mr = 1490.51)的合成、晶体结构和磁性。配合物属于单斜晶系, 空间群为C2/c, 晶胞参数如下:a = 22.295(5), b = 12.852(3), c = 20.109(4) , = 90.47(3), V = 5762(2) 3, Dc = 1.718 g/m3, Z = 4, F(000) = 3068, m = 1.701mm-1, R = 0.0915, wR = 0.1810 (based on F2)。3个中性Cu(II)大环配合物通过6个氧原子与Mn(II)配位, MnO键长范围为2.190(6)~2.208(5) 拧Mn(CuL)3]2+通过高氯酸根离子连接起来形成一个二维层。高氯酸根的氧原子与CuII键长范围为2.902~2.996 , 为弱相互作用。[Mn(H2O)6]2+, N(CN)2-和H2O位于层间, 并通过氢键连成三维网络结构。磁性研究表明CuII-MnII离子间通过草酰胺传递反铁磁相互作用, 用基于各向同性的Hamiltonian算符 = 2JMnCuMn(Cu1 + Cu2 + Cu3)进行磁性拟合得到磁耦合常数JCuMn =-17 cm-1。     

An oximate-based hexanuclear mixed-valence Mn(III)4Mn(II)2 edge-sharing bitetrahedral core with an St = 5 spin ground state

The synthesis, structures and magnetic properties of two hexanuclear Mn(6) clusters are reported: Mn(6)(mu(4)-O)(2)(dapdo)(2)(dapdoH)(4)(mu(2)-OH)(2)](ClO(4))(2).6MeCN (.6MeCN) and [Mn(6)(mu(4)-O)(2)(dapdo)(2)(dapdoH)(4)(mu(2)-OCH(3))(2)](ClO(4))(2).2Et(2)O (.2Et(2)O) [dapdo(2-) is the dianion of 2,6-diacetylpyridine dioxime and dapdoH(-) is the monoanion of the aforesaid dioxime ligand]. Both complexes are mixed-valent with two Mn(II) and four Mn(III) atoms disposed in an edge-sharing bitetrahedral core. Both complexes and display the same [Mn(III)(4)Mn(II)(2)(mu(4)-O)(2)(mu(2)-OR)(2)](10+) core in which R = H for and R = Me for . The [Mn(III)(4)Mn(II)(2)] core is rather uncommon compared to the reported [Mn(III)(2)Mn(II)(4)] core in the literature. DC magnetic susceptibility measurements on and reveal the presence of competing exchange interactions resulting in an S(t) = 5 ground spin state. The magnetic behavior of the compounds indicates antiferromagnetic coupling between the manganese(iii) centers, whereas the coupling between the manganese(iii) and manganese(ii) is weakly antiferromagnetic or ferromagnetic depending on the bridging environments. Finally the interaction between the manganese(ii) centers from the two fused tetrahedra is weakly ferromagnetic in nature stabilizing S(t) = 5 ground spin state in compounds and .     

Synthesis and characterization of a family of penta- and tetra-manganese(III) complexes derived from an assembly system containing tert-butylphosphonic acid

A family of manganese complexes, [Mn 5O 3( t-BuPO 3) 2(MeCOO) 5(H 2O)(phen) 2] ( 1), [Mn 5O 3( t-BuPO 3) 2(PhCOO) 5(phen) 2] ( 2), [Mn 4O 2( t-BuPO 3) 2(RCOO) 4(bpy) 2] (R = Me, ( 3); R = Ph, ( 4)), NBu (n) 4[Mn 4O 2(EtCOO) 3(MeCOO) 4(pic) 2] ( 5), NR' 4[Mn 4O 2( i-PrCOO) 7(pic) 2] (R' = Bu (n) , ( 6); R' = Et, ( 7)), were synthesized and characterized. The seven manganese clusters were all prepared from a reaction system containing tert-butylphosphonic acid, Mn(O 2CR) 2 (R = Me, Ph) and NR' 4MnO 4 (R' = Bu (n) , Et) with similar procedures except for using different N-containing ligands (1,10-phenanthroline (phen), 2,2'-bipyridine (bpy) and picolinic acid (picH)) as coligands. The structures of these complexes vary with the N-containing donors. Both the cores of complexes 1 and 2 feature three mu 3-O and two capping t-BuPO 3 (2-) groups bridging five Mn (III) atoms to form a basket-like cage structure. Complexes 3 and 4 both have one [Mn 4(mu 3-O) 2] (8+) core with four coplanar Mn (III) atoms disposed in an extended "butterfly-like" arrangement and two capping mu 3- t-BuPO 3 (2-) binding to three manganese centers above and below the Mn 4 plane. Complexes 5, 6, and 7 all possess one [Mn 4(mu 3-O) 2] (8+) core just as complexes 3 and 4, but they display a folded "butterfly-like" conformation with the four Mn (III) atoms nonplanar. Thus, the seven compounds are classified into three types, and three representative compounds 1.2H 2O.MeOH.MeCN , 3.6H 2O.2MeCOOH , and 5.0.5H 2O have been characterized by IR spectroscopy, ESI-MS spectroscopy, magnetic measurements and in situ UV-vis-NIR spectroelectrochemical analysis. Magnetic susceptibility measurements reveal the existence of both ferromagnetic and antiferromagnetic interactions between the adjacent Mn (III) ions in compound 1.2H 2O.MeOH.MeCN , and antiferromagnetic interactions in 3.6H 2O.2MeCOOH and 5.0.5H 2O. Fitting the experimental data led to the following parameters: J 1 = -2.18 cm (-1), J 2 = 6.93 cm (-1), J 3 = -13.94 cm (-1), J 4 = -9.62 cm (-1), J 5 = -11.17 cm (-1), g = 2.00 ( 1.2H 2O.MeOH.MeCN ), J 1 = -5.41 cm (-1), J 2 = -35.44 cm (-1), g = 2.13, zJ' = -1.55 cm (-1) ( 3.6H 2O.2MeCOOH ) and J 1 = -2.29 cm (-1), J 2 = -35.21 cm (-1), g = 2.02, zJ' = -0.86 cm (-1) ( 5.0.5H 2O ).     

Spectral and structural studies of copper(II) complexes of thiosemicarbazones derived from salicylaldehyde and containing ring incorporated at N(4)-position

Mononuclear and binuclear copper(II) complexes (1-8) with two ONS donor thiosemicarbazone ligands {salicylaldehyde 3-hexamethyleneiminyl thiosemicarbazone [H2L1] and salicylaldehyde 3-tetramethyleneiminyl thiosemicarbazone [H2L2]} have been prepared and physico-chemically characterized. IR, electronic and EPR spectra of the complexes have been obtained. The thiosemicarbazones bind to metal as dianionic ONS donor ligands in all the complexes except in [Cu(HL1)2] (2) and [Cu(HL2)2] (6). In compounds 2 and 6 the ligands are coordinated as monoanionic HL- ones. The magnetic susceptibility measurements indicate that all the complexes are paramagnetic. In complex [(CuL1)2] (1), the magnetic moment value is lower than the expected spin only value. In all the complexes g(||)>g( perpendicular)>2.0023 and G values within the range 2.5-3.5 are consistent with dx2-y2 ground state. The complexes were given the formula as [(CuL1)2] (1); [Cu(HL1)2] (2); [CuL1bpy] (3); [CuL1phen] (4); [CuL1gamma-pic].2H2O (5); [Cu(HL2)2] (6); [CuL2py].3H2O (7); [CuL2bipy] (8). The structure of the compound 8 have been solved by single crystal X-ray crystallography and was found to be distorted square pyramid around copper(II) ion.     

Polyoxometalate-supported transition metal complexes and their charge complementarity: synthesis and characterization of [M(OH)6Mo6O18[Cu(Phen)(H2O)2]2][M(OH)6Mo6O18[Cu(Phen)(H2O)Cl]2].5H2O (M = Al(+, Cr3+)

Two Anderson-type heteropolyanion-supported copper phenanthroline complexes, [Al(OH)6Mo6O18[Cu(phen)(H2O)2]2]1+ (1c) and [Al(OH)6Mo6O18[Cu(phen)(H2O)Cl]2]1- (1a) complement their charges in one of the title compounds [Al(OH)6Mo6O18[Cu(phen)(H2O)2]2][Al(OH)6Mo6O18[Cu(phen)(H2O)Cl]2].5H2O [1c][1a].5 H2O 1. Similar charge complementarity exists in the chromium analogue, [Cr(OH)6Mo6O18[Cu(phen)(H2O)2]2][Cr(OH)6Mo6O18[Cu(phen)(H2O)Cl]2].5 H2O [2c][2a].5 H2O 2. The chloride coordination to copper centers of 1a and 2a makes the charge difference. In both compounds, the geometries around copper centers are distorted square pyramidal and those around aluminum/chromium centers are distorted octahedral. Three lattice waters, from the formation of intermolecular O-H.....O hydrogen bonds, have been shown to self-assemble into an "acyclic water trimer" in the crystals of both 1 and 2. The title compounds have been synthesized in a simple one pot aqueous wet-synthesis consisting of aluminum/chromium chloride, sodium molybdate, copper nitrate, phenanthroline, and hydrochloric acid, and characterized by elemental analyses, EDAX, IR, diffuse reflectance, EPR, TGA, and single-crystal X-ray diffraction. Both compounds crystallize in the triclinic space group P. Crystal data for 1: a = 10.7618(6), b = 15.0238(8), c = 15.6648(8) angstroms, alpha = 65.4570(10), beta = 83.4420(10), gamma = 71.3230(10), V = 2182.1(2) angstroms3. Crystal data for 2: a = 10.8867(5), b = 15.2504(7), c = 15.7022(7) angstroms, alpha = 64.9850(10), beta = 83.0430(10), gamma = 71.1570(10), V = 2235.47(18) angstroms3. In the electronic reflectance spectra, compounds 1 and 2 exhibit a broad d-d band at approximately 700 nm, which is a considerable shift with respect to the value of 650-660 nm for a square-pyramidal [Cu(phen)2L] complex, indicating the coordination of [M(OH)6Mo6O18]3- POM anions (as a ligand) to the monophenanthroline copper complexes to form POM-supported copper complexes 1c, 1a, 2c, and 2a. The ESR spectrum of compound 1 shows a typical axial signal for a Cu2+ (d9) system, and that of compound 2, containing both chromium(III) and copper(II) ions, may reveal a zero-field-splitting of the central Cr3+ ion of the Anderson anion, [Cr(OH)6Mo6O18]3-, with an intense peak for the Cu2+ ion.     

Syntheses and magnetic properties of hexanuclear [Cp2Mn3(L1)4]2 and octanuclear [Mn8(L2)12(mu 4-O)2] (L1 = 2-HNC5H5N,L2 = 2-NH-3-Br-5-MeC5H3N,Cp = C5H5)

The reactions of manganocene, Cp2Mn, with 2-aminopyridine (L1H) or 2-amino-3-bromo-5-methylpyridine (L2H) give the novel hexanuclear and octanuclear Mn(II) amido cage compounds [Cp2Mn3(L1)4]2 (1) and [Mn8(L2)12(mu 4-O)2] (2); magnetic measurements on which provide a rare insight into the magnetic properties of amido-bridged metal clusters.     

Heterobimetallic hexanuclear [Mn(ΙΙΙ)4Ln(ΙΙΙ)2] clusters: a rare Mn(ΙΙΙ)4Nd(ΙΙΙ)2 example exhibiting slow relaxation of magnetization

Reactions of lanthanide perchlorates and manganese acetate with Schiff-base ligand (H(4)L = 2-(((2-hydroxy-3-methoxyphenyl)methylene)amino)-2-(hydroxymethyl)-1,3-propanediol) in methanol in the presence of triethylamine yielded two hexanuclear heterometallic clusters of general formula [Mn(4)(ΙΙΙ)Ln(2)(ΙΙΙ)(H(2)L)(2)(HL)(2)(CH(3)COO)(4)(CH(3)O)(2)(CH(3)OH)(4)](ClO(4))(2)·6CH(3)OH [Ln = La(ΙΙΙ) (1), Nd(ΙΙΙ) (2)]. 1 and 2 are isostructural, with the metal centres consisting of a nonplanar [Mn(4)(ΙΙΙ)Ln(2)(ΙΙΙ)(μ(2)-O)(8)(μ(3)-OR)(2)](8+) core. Variable-temperature solid state magnetic susceptibilities measurements of 1 and 2 in the temperature 2-300 K were performed, indicating dominant antiferromagnetic exchange interactions between the metal centres in both compounds. Alternating current (ac) susceptibility data for 2 displays out-of-phase signal suggesting slow relaxation of magnetization whereas no out-of-phase signal is observed in 1, highlighting the incorporation of lighter lanthanide leads to SMM property.     

Structures and magnetic properties of an antiferromagnetically coupled polymeric copper(II) complex and ferromagnetically coupled hexanuclear nickel(II) clusters

Reactions between 2,6-diformyl-4-methylphenol (DFMF) and tris(hydroxymethyl) aminomethane (THMAM = H(3)L2) in the presence of copper(II) salts, CuX(2) (X = CH(3)CO(2)(-), BF(4)(-), ClO(4)(-), Cl(-), NO(3)(-)) and Ni(CH(3)CO(2))(2) or Ni(ClO(4))(2)/NaC(6)H(5)CO(2), sodium azide (NaN(3)), and triethylamine (TEA), in one pot self-assemble giving a coordination polymer consisting of repeating pentanuclear copper(II) clusters {[Cu(2)(H(5)L(2-))(μ-N(3))](2)[Cu(N(3))(4)]·2CH(3)OH}(n) (1) and hexanuclear Ni(II) complexes [Ni(6)(H(3)L1(-))(2)(HL2(2-))(2)(μ-N(3))(4)(CH(3)CO(2))(2)]·6C(3)H(7)NO·C(2)H(5)OH (2) and [Ni(6)(H(3)L1(-))(2)(HL2(2-))(2)(μ-N(3))(4)(C(6)H(5)CO(2))(2)]·3C(3)H(7)NO·3H(2)O·CH(3)OH (3). In 1, H(5)L(2-) and in 2 and 3 H(3)L1(-) and HL2(2-) represent doubly deprotonated, singly deprotonated, and doubly deprotonated Schiff-base ligands H(7)L and H(4)L1 and a tripodal ligand H(3)L2, respectively. 1 has a novel double-stranded ladder-like structure in which [Cu(N(3))(4)](2-) anions link single chains comprised of dinuclear cationic subunits [Cu(2)(H(5)L(2-))(μ-N(3))](+), forming a 3D structure of interconnected ladders through H bonding. Nickel(II) clusters 2 and 3 have very similar neutral hexanuclear cores in which six nickel(II) ions are bonded to two H(4)L1, two H(3)L2, four μ-azido, and two μ-CH(3)CO(2)(-)/μ-C(6)H(5)CO(2)(-) ligands. In each structure two terminal dinickel (Ni(2)) units are connected to the central dinickel unit through four doubly bridging end-on (EO) μ-azido and four triply bridging μ(3)-methoxy bridges organizing into hexanuclear units. In each terminal dinuclear unit two nickel centers are bridged through one μ-phenolate oxygen from H(3)L1(-), one μ(3)-methoxy oxygen from HL2(2-), and one μ-CH(3)CO(2)(-) (2)/μ-C(6)H(5)CO(2)(-) (3) ion. Bulk magnetization measurements on 1 show moderately strong antiferromagnetic coupling within the [Cu(2)] building block (J(1) = -113.5 cm(-1)). Bulk magnetization measurements on 2 and 3 demonstrate that the magnetic interactions are completely dominated by ferromagnetic coupling occurring between Ni(II) ions for all bridges with coupling constants (J(1), J(2), and J(3)) ranging from 2.10 to 14.56 cm(-1) (in the ? = -J(1)(?(1)?(2)) - J(1)(?(2)?(3)) - J(2)(?(3)?(4)) - J(1)(?(4)?(5)) - J(1)(?(5)?(6)) - J(2)(?(1)?(6)) - J(3)(?(2)?(6)) - J(3)(?(2)?(5)) - J(3)(?(3)?(5)) convention).     

2，6-二氯苯甲酸桥联的双核锰配合物的水热合成与晶体结构

A dinuclear manganese(Ⅱ) complex, [Mn₂(L¹)₂(phen)₄]·(ClO₄)₂ (1), has been synthesized and structurally characterized (HL¹=2,6-dichlorobenzoic acid, phen=1,10-phenanthroline). It crystallizes in triclinic system, space group P1 with a=1.112 3(4) nm, b=1.378 2(4) nm, c=2.085 7(3) nm, α=93.768(2)°, β=90.606(10)°, γ=95.606(3)°, V=3.174 8(15) nm³, Z=2, C₆₂H₃₈C₁₆Mn₂N₈O₁₂, M_r=1 409.58, D_c=1.475 g·cm^-3, μ=0.718 mm^-1, F(000)=1 428, R=0.064 3, wR=0.138 3. In the crystal the manganese atom is six-coordinated by two oxygen atoms from two different 2,6-dichlorobenzolate molecules and four nitrogen atoms from two 1,10-phenanthroline molecules, completing an octahedral geometry. CCDC: 692296.     

New valence-sandwich [Mn(II)4Mn(III)4Mn(II)4] aggregate showing single-molecule magnet behavior

The reaction of manganese(II) acetate, 1,1,1-tris(hydroxymethyl)methane (H3thme), and triethylamine in methanol leads to the formation of [Mn12O2(OMe)2(thme)4(OAc)10(H2O)4].2MeOH. The [Mn(III)4Mn(II)8] core consists of a central [Mn(III)4O6] rhombus sandwiched by two [Mn(II)4O7] fragments. Frequency-dependent ac susceptibility and hysteresis loops in the magnetization indicate single-molecule magnet behavior with a pure quantum-tunneling regime of relaxation below 0.2 K.