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1.
Chem Commun (Camb) ; (16): 1745-7, 2006 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-16609791

RESUMO

This communication reports the first example of cyclic ferric clusters with an odd number of iron atoms capped by phosphonate ligands, namely, [Fe9(mu-OH)(7)(mu-O)2(O3PC6H9)8(py)12]. The magnetic studies support a S = 1/2 ground state with an exchange coupling constant of about J approximately equal to -30 K.

2.
Chem Commun (Camb) ; (9): 1076-7, 2003 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-12772910

RESUMO

Compound Na6Co7(hedp)2(hedpH)4(H2O)4 x 8H2O (hedp = 1-hydroxyethylidenediphosphonate) with a novel layer structure is reported in this paper. The layer maybe viewed as made up from two types of chains each of composition Co3(hedp)2 and Co2(hedpH)2. Magnetic measurements at 1.8 K reveal a metamagnetic transition at ca. 6.5 kOe, followed by a second transition to a ferromagnetic state at ca. 30 kOe.

3.
Inorg Chem ; 38(22): 5061-5066, 1999 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-11671251

RESUMO

Three new copper(II) diphosphonates, (NH(4))(2)Cu(3)(hedp)(2)(H(2)O)(4) (1), [NH(3)(CH(2))(4)NH(3)]Cu(3)(hedp)(2).2H(2)O (2), and [NH(2)(C(2)H(4))(2)NH(2)]Cu(3)(hedp)(2) (3), where hedp = 1-hydroxyethylidenediphosphonate, have been synthesized and characterized by single-crystal structural analysis. Crystal data: 1, monoclinic, P2(1)/n, a = 6.2137(13) Å, b = 14.747(2) Å, c = 11.1802(12) Å, beta = 105.83(2) degrees, Z = 2; 2, triclinic, P&onemacr;, a = 7.4840(12) Å, b = 8.032(3) Å, c = 10.007(2) Å, alpha = 111.68(2) degrees, beta = 96.188(14) degrees, gamma = 96.97(2) degrees, Z = 1; 3, triclinic, P&onemacr;, a = 7.0155(6) Å, b = 8.0904(9) Å, c = 9.2644(11) Å, alpha = 112.611(13) degrees, beta = 90.819(8) degrees, gamma = 92.824(7) degrees, Z = 1. The compound 1 is composed of infinite chains with a ladder-type motif. The compounds 2 and 3 adopt a two-dimensional layer structure which contains four- and eight-membered rings assembled from vertex-sharing {CuO(4)} units and {CPO(3)} tetrahedra. The magnetic properties of 3 have been investigated.

5.
Inorg Chem ; 45(1): 59-65, 2006 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-16390040

RESUMO

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.

6.
Inorg Chem ; 44(8): 2761-5, 2005 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-15819563

RESUMO

This paper reports the syntheses and characterization of four isomorphous compounds (NH(3)C(6)H(4)NH(3))M(2)(hedpH)(2).H(2)O [M = Fe (1), Co (2), Mn (3), Zn (4); hedp = C(CH(3))(OH)(PO(3))(2)]. Each contains two crystallographically different kinds of {M(2)(hedpH)(2)}(n) double chains, where the {M(2)(mu-O)(2)} dimer units are connected by O-P-O bridges. The double chains are connected through extensive hydrogen bonds, hence generating a three-dimensional supramolecular network. The temperature-dependent magnetic susceptibility measurements show dominant antiferromagnetic interactions in compounds 1-3, mediated through the mu-O and/or O-P-O bridges between the metal(II) centers. The magnetization measurements reveal that compounds 1-3 experience field-induced magnetic transitions at low temperatures.

7.
Inorg Chem ; 41(16): 4084-6, 2002 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-12160388

RESUMO

This paper reports the synthesis and crystal structure of a novel mixed valence copper(I,II) compound, Cu(I)(2)Cu(II)(hedpH(2))(2)(4,4'-bpy)(2).2H(2)O (1), where hedp represents 1-hydroxyethylidenediphosphonate. The structure is composed of [Cu(I)(2)Cu(II)(hedpH(2))(2)] trimer units and 4,4'-bipyridine linkages, forming a two-dimensional brick-wall-like layer structure in the ab plane. The layers are stacked along the [001] direction with strong interlayer hydrogen bonds and pi-pi interactions, thus leading to the construction of a three-dimensional network.

8.
Inorg Chem ; 43(6): 2151-6, 2004 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-15018539

RESUMO

This paper reports two new cobalt phosphonate compounds [NH3(CH2)nNH3]Co2(hedpH)2.2H2O [n = 4 (1), 5 (2)], where hedp is (1-hydroxyethylidene)diphosphonate [CH3C(OH)(PO3)2]. Both contain ladderlike chains with the same composition [Co2(hedpH)2](n)(2n-), where edge-shared [CoO6] octahedra are each bridged by O-P-O units. The chains are linked by very strong hydrogen bonds to form a three-dimensional open network with channels in which the diammonium counterions and lattice water reside. Magnetic studies reveal dominant antiferromagnetic interactions between the Co centers within the chain in both compounds. The field dependent magnetization confirms the occurrence of the field-induced magnetic transitions, with the critical fields ca. 25 kOe for 1 and 27.5 kOe for 2, respectively. In the case of compound 2, weak ferromagnetism is also observed at very low temperatures, possibly arising from spin canting of the antiferromagnetically coupled Co(II) ions in the chain. Crystal data: 1, monoclinic, P2(1)/c, a = 5.4868(8), b = 12.9116(18), and c = 15.251(2) A, beta = 98.843(2) degrees, V = 1067.6(3) A(3), Z = 2; 2, monoclinic, P2(1)/c, a = 5.4757(7), b = 12.7740(16), and c = 15.794(2) A, beta = 98.797(2) degrees, V = 1091.7(2) A(3), Z = 2.

9.
Acta Crystallogr C ; 59(Pt 8): m310-2, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12909752

RESUMO

In the title compound, [1,4-bis(diphenylphosphino)butane-2kappa(2)P,P']di-mu-thio-1:2kappa(4)S-dithio-1kappa(2)S-palladium(II)tungsten(VI) N,N'-dimethylformamide hemisolvate hemihydrate, [PdWS(4)(C(28)H(28)P(2))].0.5C(3)H(7)NO.0.5H(2)O, the Pd atom is coordinated by two S atoms from the distorted-tetrahedral [WS(4)](2-) anion and two P atoms from the dppb molecule [dppb is 1,4-bis(diphenylphosphino)butane] in an approximately square-planar configuration. A puckered seven-membered ring is formed by the Pd atom and the dppb ligand.

10.
Acta Crystallogr C ; 59(Pt 10): M390-1, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14532651

RESUMO

The title compound, [Ag(3)WIS(4)(C(17)H(14)NP)(3)].0.5CH(2)Cl(2), is a cubane-type heterometallic cluster containing diphenyl(2-pyridyl)phosphine (Ph(2)PPy). The pyridyl group of Ph(2)PPy remains uncoordinated, so the Ph(2)PPy ligand is monodentate and coordinates to one Ag atom. The W atom and three Ag atoms form a distorted tetrahedral geometry, capped by one I atom and three S atoms.

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