{Zn6[MeN(CH2CO2)(CH2PO3)]6(Zn)}4- Anion: The First Example of the Oxo-Bridged Zn6 Octahedron with a Centered Zn(II) Cation

Synthesis and crystal structure of a novel cobalt phosphonate containing the [Co(H2O)6]2+ cation

Reaction of hexamethylenediaminetetrakis(methylphosphonic acid), [(H2O3PCH2)2N(CH2)6N(CH2PO3H2)2] (H8L), with cobalt nitrate affords a novel phosphonate, [Co(H2O)6][Co(H2O)4(H6L)2]·12H2O (1), and its structure was determined by X-ray diffraction analysis.

Formation of a non-porous cobalt-phosphonate framework by small pH change in the preparation of the microporous STA-16(Co)

The initial pH of the suspension was found to determine whether the porous STA-16(Co) phase or a non-porous Co(ii)-phosphonate pillared layer structure was formed.

Sodium-centered dodecanuclear Co(II) and Ni(II) complexes with 2-(phosphonomethylamino)succinic acid: studies of spectroscopic, structural, and magnetic properties

Two new isostructural cobalt(II) and nickel(II) polynuclear complexes with 2-(phosphonomethyl)aminosuccinic acid, H4PMAS, namely, Na[Co12(PMAS)6(H2O)17(OH)]·x2H2O, 1·x2H2O, and Na[Ni12(PMAS)6(H2O)17(OH)]·xH2O, 2·xH2O, have been synthesized for the first time from aqueous solutions and studied by single crystal X-ray diffraction, infrared, and UV-visible diffuse reflectance spectroscopy; TG/DTA analysis; and magnetochemistry. Both 1 and 2 crystallize in the rhombohedral crystal system with the R3[overline] space group with 1/6 of the Co12(PMAS)6 or Ni12(PMAS)6 moieties in the asymmetric unit. The X-ray refinements reveal the presence of 18 water sites, but unit cell charge balance requires that one water molecule must be an OH(-) anion, an anion which is disordered over the 18 sites. The PMAS(4-) ligand forms two five-membered and one six-membered chelation ring. Both 1 and 2 contain 24-membered metallacycles as a result of the bridging nature of the PMAS(4-) ligands. The resulting three-dimensional structures have one-dimensional channels with a sodium cation at the center of symmetry. The temperature dependence of the magnetic susceptibility reveals the presence of weak antiferromagnetic exchange coupling interactions in both 1 and 2. Two exchange coupling constants, J1 = -15.3(7) cm(-1) and J2 = -1.06(2) cm(-1) with S1 = S2 = 3/2 for the Co(1)···Co(1) and Co(1)···Co(2) exchange pathways, respectively, are required for 1, and J1 = -1.17(6) cm(-1) and J2 = -4.00(8) cm(-1) with S1 = S2 = 1 for the Ni(1)···Ni(1) and Ni(1)···Ni(2) exchange pathways, respectively, are required for 2, in order to fit the temperature dependence of the observed magnetic susceptibilities.

Synthesis and Characterization of Four Metal−Organophosphonates with One-, Two-, and Three-Dimensional Structures

A series of metal-organic hybrid compounds were synthesized using two new phosphonic acids, pyridyl-4-phosphonic acid and p-xylylenediphosphonic acid (H(2)O(3)PCH(2)C(6)H(4)CH(2)PO(3)H(2)). The phosphonic acid ligands have been synthesized from their corresponding bromides following two different types of reactions. The reaction of pyridyl-4-phosphonic acid with three different divalent metal salts results in the formation of molecular structures of different dimensionality. The reaction of Cu(II) with the phosphonic acid under hydrothermal conditions yields a three-dimensional (3D) open framework structure having the molecular formula [Cu(4)(NC(5)H(4)-PO(3))(4)(H(2)O)(10)] (1). The reactions with Mn(II) and Zn(II) salts with the same phosphonic acid resulted in a two-dimensional layered and a dinuclear compound with molecular formulas [Mn(3)(NC(5)H(4)-PO(3))(4)(H(2)O)(6)(ClO(4))(2)] (2) and [Zn(2)(NHC(5)H(4)-PO(3)H)(2)Cl(4)] (3), respectively. Compound 1 crystallizes in the triclinic crystal system having space group P with structural parameters a = 7.4564(15) Angstrom, b = 9.1845(19) Angstrom, c = 11.582(2) Angstrom, alpha = 100.842(3) degrees, beta = 104.303(3) degrees, gamma = 94.774(3) degrees, and Z = 1. Compound 2 crystallizes in the triclinic crystal system, space group P, with structural parameters a = 7.6871(14) Angstrom, b = 10.576(2) Angstrom, c = 14.470(3)Angstrom, alpha = 81.340(3) degrees, beta = 81.561(3) degrees, gamma = 68.757(3) degrees, and Z = 2, whereas compound 3 crystallizes in a monoclinic crystal system with space group P2(1)/n. The structural parameters are as follows: a = 8.4969 (5) Angstrom, b = 9.3911 (5) Angstrom, c = 12.3779 (6) Angstrom, beta = 90.860(17) degrees, and Z = 4. The pyridylphosphonate ligand shows different ligation behavior toward the three divalent metal ions. On the other hand, p-xylylenediphosphonic acid on reaction with Co(II) formed a 3D compound [Co(2)(O(3)PCH(2)C(6)H(4)CH(2)PO(3))(2)(H(2)O)(2)] (4) with a layered and pillared structure. Compound 4 crystallizes in an orthorhombic crystal system with space group Pnma. The structural parameters are a = 21.744(4) Angstrom, b = 5.6744(10) Angstrom, c = 4.7927(9) Angstrom, and Z = 4.

Rational design and synthesis of porous organic-inorganic hybrid frameworks constructed by 1,3,5-benzenetriphosphonic acid and pyridine synthons

1,3,5-Benzenetriphosphonic acid, H6BTP, 1,3,5-[(HO)2OP]3C6H3, was reacted hydrothermally with copper salts in the absence and presence of 4,4'-bipyridine (bpy) and 4,4'-trimethlyenedipyridine (tbpy) in a 1:1 molar ratio leading to three new organic-inorganic hybrid frameworks. Compound 1, {Cu6[C6H3(PO3)3]2(H2O)8} x 5.5 H2O, has three different copper ions that are interconnected by the highly charged [1,3,5-(PO3)3C6H3]6- anionic moieties. These moieties self-assemble through tetra-copper units to give a cagelike motif with two benzene rings parallel to each other at a distance of 3.531 A which extend along the a axis and link with a grouping of four-coordinated copper units in the b axis direction to give the cross-linked layered structure. In compound 2, Cu{C6H3[PO(OH)O]2[PO(OH)2]}(C10H8N2), the copper ions are in square pyramidal geometries and are interconnected via chelating and bridging BTP ligands into layers which are further cross-linked by bpy ligands into a pillared layered architecture. Compound 3, {Cu2C6H3[PO(OH)O]2[PO3](C13H14N2)} x 3 H2O x 0.5 HCON(CH3)2, contains tetra-copper units that are linked by BTP ligands and further linked by tbpy linkers in the c axis direction to produce a large channel-sized 3D framework.

Studies on Cage-Type Tetranuclear Metal Clusters with Ferrocenylphosphonate Ligands

Reaction of FcCH(2)PO(3)H(2) [Fc=(eta(5)-C(5)H(5))Fe(eta(5)-C(5)H(4))] (H(2)FMPA) and 1,10-phenanthroline (phen) with Cd(OAc)(2).2 H(2)O or ZnSO(4).7 H(2)O in methanol in the presence of triethylamine resulted in the formation of two new ferrocenylphosphonate metal-cage complexes [M(4)(fmpa)(4)(phen)(4)] 7 CH(3)OH (M=Cd 1, M=Zn 2). Both structures contain two kinds of isomeric tetranuclear metal phosphonate cages, which are linked to one another by pi-pi interactions between the phen molecules. In 1, the Cd1, Cd3, and Cd4 atoms are all pentacoordinate, while the Cd2 atom is coordinated by four oxygen atoms from three phosphonate ligands and two nitrogen atoms from the chelating phen in a distorted octahedral geometry. Four Cd atoms from each unit are interconnected through bridging phosphonate ligands with different coordination modes, such as 5.221, 4.211, and 2.11 (Harris notation), yielding a {Cd(4)} cage. In 2, each Zn atom is coordinated by three oxygen atoms from three phosphonate ligands and two nitrogen atoms from phen, leading to a distorted square-pyramidal geometry. The four Zn atoms of each isomeric unit are also interconnected through four bridging phosphonate ligands to yield a {Zn(4)} cage. Fluorescent studies indicate that ligand-to-ligand charge-transfer photoluminescence is observed for 1, while the emission bands of 2 can be assigned to an admixture of ligand-to-ligand and metal-to-ligand charge transfer. Solution-state differential pulse voltammetry indicates that the half-wave potentials of the ferrocenyl moieties in 1 and 2 have different deviations relative to the relevant H(2)FMPA ligand. This may be because the highest occupied molecular orbital (HOMO) in 1 is located in the FMPA(2-) groups, while in 2 the HOMO is located in the phen and Zn(II) groups, so the Fe(II) centers in complex 1 are more easily oxidized to Fe(III) centers than those of 2. The third-order nonlinear optical (NLO) measurements show that both 1 and 2 exhibit strong third-order NLO self-focusing effects; hence, they are promising candidates for NLO materials. By calculating the component of the lowest unoccupied molecular orbitals of 1 and 2, we confirmed that the co-planar phen rings control their optical nonlinearity, while the H(2)FMPA ligands and metal ions have only a weak influence on their NLO properties.

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.

Ionic Solid-State Dimers and Polymers Derived from Imidazolium Dicarboxylic Acids

A series of imidazolium dicarboxylic acids have been prepared from the reaction of the 1,3-bis(carboxymethyl)imidazolium zwitterion with the Brønsted acids HX (X = F, Br, Cl, ClO4). The structures of these acids have been established in the solid state by single-crystal X-ray diffraction, which revealed that the cations and anions form strong hydrogen bonds through O-H...X interactions, leading to the formation of dimeric and polymeric networks. These acids react with elemental zinc and cobalt to form stable polymeric coordination complexes, some of which have also been characterised by X-ray diffraction.

Assembly of Lipophilic Tetranuclear (Cu4 and Zn4) Molecular Metallophosphonates from 2,4,6-Triisopropylphenylphosponic Acid and Pyrazole Ligands

A sterically hindered aryl phosphonic acid ArP(O)(OH)2 (2) (Ar = 2,4,6-isopropylphenyl) was synthesized and structurally characterized. ArP(O)(OH)2 forms an interesting hydrogen-bonded corrugated sheet-type supramolecular structure in the solid-state. A three-component reaction involving ArP(O)(OH)2, 3,5-dimethylpyrazole(DMPZH), and Cu(CH3COO)2.H2O produces the tetranuclear Cu(II) compound [Cu4(mu3-OH)2{ArPO2(OH)}2(CH3CO2)2(DMPZH)4][CH3COO]2.CH2Cl2 (3). A similar three-component reaction involving ArP(O)(OH)2, 3,5-dimethylpyrazole, and Zn(CH3COO)2.2H2O yields the tetranuclear Zn(II) compound [Zn4{ArPO3}2{ArPO2(OH)}2{DMPZH}4(DMPZ)2].5MeOH (4). While 3 has been found to have an asymmetric cage structure where two dinuclear copper cores are bridged by bidentate [ArPO2(OH)]- ligands, 4 possesses an open-book tricyclic structure composed of three fused metallophosphonate rings. Magnetic studies on 3 revealed antiferromagnetic behavior.

Dodecanuclear Manganese(III) Phosphonates with Cage Structures

Treatments of Mn(O(2)CR)(2) (R = Me, Ph) with NBu(4)MnO(4) in CH(3)CN or CH(3)CN/CH(2)Cl(2) in the presence of acetic acid, delta(1)-cyclohexenephosphonic acid (C(6)H(9)PO(3)H(2)), and 2,2'-bipyridine or 1,10-phenanthroline result in three novel dodecamanganese(III) clusters [Mn(12)O(8)(O(2)CMe)(6)(O(3)PC(6)H(9))(7)(bipy)(3)] (1), [Mn(12)O(8)(O(2)CPh)(6)(O(3)PC(6)H(9))(7)(bipy)(3)] (2), and [Mn(12)O(8)(O(2)CPh)(6)(O(3)PC(6)H(9))(7)(phen)(3)] (3). They have a similar Mn(12) core of [Mn(III)(12)(mu(4)-O)(3)(mu(3)-O)(5)(mu-O(3)P)(3)] with a new type of topologic structure. Solid-state dc magnetic susceptibility measurements of complexes 1-3 reveal that dominant antiferromagnetic interactions are propagated between the magnetic centers. The ac magnetic measurements suggest an S = 2 ground state for compounds 1 and 3 and an S = 3 ground state for compound 2.

[Zn7{(2-C5H4N)CH(OH)PO3}6(H2O)6]SO4·4H2O: A Zinc Phosphonate Cluster with a Drum-like Cage Structure

Direct reaction of hydroxy(2-pyridyl)methylphosphonic acid with zinc sulfate under hydrothermal conditions results in the formation of the novel heptanuclear cluster compound [Zn7{(2-C5H4N)CH(OH)PO3}6 (H2O)6]SO4 x 4H2O (1). The inorganic core of the cluster can be described as a cylindrical drum made up of six Zn atoms bridged by six {CPO3} units that is centered by a seventh Zn atom. Crystal data: monoclinic, C2/c, a = 22.690(2) A, b = 16.675(2) A, c = 18.151(2) A, beta = 93.390(2) degrees.

New Types of Blue, Red or Near IR Luminescent Phosphonate-Decorated Lanthanide Oxalates

Hydrothermal reactions of the lanthanide chlorides with MeN(CH2CO2H)(CH2PO3H2), (H3L1) (or Me2NCH2PO3H2, H2L2) and sodium oxalate lead to seven new lanthanide oxalate phosphonate hybrids with three types of 3D network structures, namely, [Ln(C2O4){MeNH(CH2CO2)(CH2PO3H)}]0.5 H2O (Ln=Nd: 1; Eu: 2; Gd: 3), [Ln4(C2O4)5(Me2NHCH2PO3)2(H2O)4]2 H2O (Ln=La: 4, Nd: 5), [Ln3(C2O4)4(Me2NHCH2PO3)(H2O)6]6 H2O (Gd: 6, Er: 7). Their structures have been established by X-ray single-crystal diffraction. Complexes 1-3 are isostructural and feature a 3D network formed by the interconnection of 3D network of {Ln(H2L1)}2+ with 1D chains of {Ln(C2O4)}+. Complexes 4 and 5 are isostructural and feature a complex 3D network built from 3D network of lanthanide oxalate and {Ln4(HL2)2} units. The isostructural 6 and 7 form another type of 3D network composed of porous lanthanide-oxalate network inserted by 1D chains of lanthanide-oxalate phosphonate. Compounds 1, 5 and 7 are luminescent materials in the near IR region. Compounds 3 and 6 exhibit a broad blue fluorescent emission band at 451 and 467 nm, respectively. Compound 2 displays very strong and sharp emission bands at 592, 616 and 699 nm with a long luminescent lifetime of 1.13 ms.

New Zinc Phosphates Decorated by Imidazole-Containing Ligands

Four new zinc phosphates [Zn(HPO4)(C6H9N3O2)] (1), [Zn(HPO4)(C4H6N2)].H2O (2), [Zn2(HPO4)2(C14H14N4)].2H2O (3), and [Zn(HPO4)(C14H14N4)] (4) were synthesized in the presence of d-histidine, 1-methylimidazole, 1,4-bis(imidazol-1-ylmethyl)benzene (L1), and 1,2-bis(imidazol-1-ylmethyl)benzene (L2), respectively, and their structures were determined by X-ray crystallography. The inorganic framework of compounds 1, 2, and 3 is composed of vertex-shared ZnO3N and HPO4 tetrahedra that form four rings, which, in turn, are linked to generate a one-dimensional ladder structure. In 1 and 2 the organic groups (monoimidazole ligand) are located at each side of the ladders, while in 3 the bisimidazole ligand, 1,4-bis(imidazol-1-ylmethyl)benzene, links the ladders together to form a novel 2D structure. Compound 1 is the first zinc phosphate framework to be templated by an N-bonded chiral amino acid. In 4 the zero-dimensional four rings are joined together by the linear bridging ligand, 1,2-bis(imidazol-1-ylmethyl)benzene, to generate a one-dimensional framework with a new face-to-face structural motif. The 3D structure of compound 4 is stabilized by hydrogen-bonding, pi-pi interactions, and C-H...pi interactions. The approach of incorporating multifunctional ligands into zinc phosphate frameworks and linking the inorganic zinc phosphates subunits by an organic ligand provides opportunities for the design of new inorganic-organic open frameworks.