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M. Concepción Gimeno

Publications and source records attributed to M. Concepción Gimeno.

5 recordsLinked to original sources
PubMed1998

Theoretical Evidence for Transannular Metal-Metal Interactions in Dinuclear Coinage Metal Complexes.

The dinuclear head-to-tail complexes [M(2)(PPh(2)CH(2)SPh)(2)](2+) (M = Cu (1), Ag (2a, 2b), Au (4)) are obtained either by reaction of [Cu(CH(3)CN)(4)]CF(3)SO(3), AgClO(4), AgCF(3)SO(3), with equimolecular amounts of PPh(2)CH(2)SPh or of [AuCl(PPh(2)CH(2)SPh)] (3), prepared by reaction of [AuCl(tht)] and PPh(2)CH(2)SPh, with AgCF(3)SO(3). The crystal structures of complexes 2a and 4 have been established by X-ray diffraction studies. Ab initio HF/II and MP2/II calculations have been performed on the [M(2)(H(2)PCH(2)SH)(2)](2+) model, indicating that metallophilic attraction is indeed present for all the coinage metals as a correlation effect and is strengthened in the case of gold by relativistic effects. Since experimental and theoretically predicted geometries are in close agreement, we assume that our calculations are accurate enough to obtain valid conclusions.

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PubMed1998

Dithiocarbamate Ligands as Building-Blocks in the Coordination Chemistry of Gold.

The monodentate dithiocarbamate complexes [Au(2)(S(2)CNR(2))(2){&mgr;-(PPh(2))(2)C=CH(2)}] (R = Me (1), Et (2), Bz (3)) are obtained by reaction of [Au(2)Cl(2){&mgr;-(PPh(2))(2)C=CH(2)}] with NaS(2)CNR(2). The free sulfur atoms in complex 2 can subsequently be used to coordinate a third metal center, giving the trinuclear derivatives [Au(2)M(&mgr;-S(2)CNEt(2))(2){&mgr;-(PPh(2))(2)C=CH(2)}]X (X = ClO(4), M = Au (5), Ag (6); X = PF(6), M = Cu (7)). The dinuclear tricoordinate gold(I) complexes [Au(2)(&mgr;-S(2)CNEt(2)){&mgr;-(PPh(2))(2)C=CH(2)}(2)]ClO(4) (8) and [Au(2)(&mgr;-S(2)CNEt(2)){&mgr;-(PPh(2))(2)C=CH(2)}(PPh(3))(2)]ClO(4) (9) are obtained by reaction of [Au(2)(&mgr;-S(2)CNEt(2)){&mgr;-(PPh(2))(2)C=CH(2)}]ClO(4) (4) with (PPh(2))(2)C=CH(2) or PPh(3). The former is also obtained by reaction of [Au(2){&mgr;-(PPh(2))(2)C=CH(2)}(2)](ClO(4))(2) with sodium N,N-diethyldithiocarbamate (1:1). The crystal structures of complexes 2 and 8 are established by X-ray crystallography.

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PubMed1997

Tris(amido)tingold Complexes in Different Oxidation States. First Structural Characterization of a Sn-Au-Au-Sn Linear Chain.

The reaction of [MeSi{Me(2)SiN(Li)(p-tol)}(3)(Et(2)O)(2)] with SnCl(2) in a 1:1 molar ratio leads the tris(amido)stannate [MeSi{Me(2)SiN(p-tol)}(3)SnLi(Et(2)O)] (1), which further reacts with neutral [AuCl(PPh(3))] and anionic [PPN][AuCl(2)], PPN[AuRCl] (R = C(6)F(5), mes), and chlorogold(I) complexes yielding [Au(MeSi{Me(2)SiN(p-tol)}(3)Sn)(PPh(3))] (2) and [PPN][Au(MeSi{Me(2)SiN(p-tol)}(3)Sn)(2)] (3) and [Au(MeSi{Me(2)SiN(p-tol)}(3)Sn)(R)] (R = C(6)F(5), 4; R = mes, 5), respectively. The reaction of 1 with the dinuclear gold(II) derivative [Au(2)(CH(2)PPh(2)CH(2))(2)Cl(2)] in a 1:2 ratio affords [Au(2)(CH(2)PPh(2)CH(2))(2)(MeSi{Me(2)SiN(p-tol)}(3)Sn)(2)] (6). In a similar way but starting from PPN[Au(C(6)F(5))(3)Cl] and reacting with 1 in a 1:1 ratio, the Au(III) complex [PPN][Au(MeSi{Me(2)SiN(p-tol)}(3)Sn)(C(6)F(5))(3)] (7) has been obtained. X-ray crystal structure analyses were performed for compounds 2 and 6, establishing the Sn-Au bonds [d(Au-Sn) = 2.5651(13) and 2.6804(13) Å, respectively). Compound 6 has a nearly linear Sn-Au-Au-Sn array and features the first examples of tin-gold(II) bonds.

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PubMed1996

Gold(I) Complexes with the nido-Diphosphino Ligand [7,8-(Ph(2)P)(2)-7,8-C(2)B(9)H(10)](-). Preparation of the First Metallocarborane Complex of this Ligand. Crystal Structures of [Au{(PPh(2))(2)C(2)B(9)H(10)}(PPh(3))].CH(2)Cl(2) and [Au(2){(PPh(2))(2)C(2)B(9)H(10)}(2){(PPh(2))(2)(CH(2))(3)}].3Me(2)CO.

The reaction of [AuCl(PR(3))] with [1,2-(Ph(2)P)(2)-1,2-C(2)B(10)H(10)] in refluxing ethanol proceeds with partial degradation (removal of a boron atom adjacent to carbon) of the closo species to give [Au{(PPh(2))(2)C(2)B(9)H(10)}(PR(3))] [PR(3) = PPh(3) (1), PPh(2)Me (2), PPh(2)(4-Me-C(6)H(4)) (3), P(4-Me-C(6)H(4))(3) (4), P(4-OMe-C(6)H(4))(3) (5)]. Similarly, the treatment of [Au(2)Cl(2)(&mgr;-P-P)] with [1,2-(Ph(2)P)(2)-1,2-C(2)B(10)H(10)] under the same conditions leads to the complexes [Au(2){(PPh(2))(2)C(2)B(9)H(10)}(2)(&mgr;-P-P)] [P-P = dppe = 1,2-bis(diphenylphosphino)ethane (6), dppp = 1,3-bis(diphenylphosphino)propane (7)], where the dppe or dppp ligands bridge two gold nido-diphosphine units. The reaction of 1 with NaH leads to removal of one proton, and further reaction with [Au(PPh(3))(tht)]ClO(4) gives the novel metallocarborane compound [Au(2){(PPh(2))(2)C(2)B(9)H(9)}(PPh(3))(2)] (8). The structure of complexes 1 and 7 have been established by X-ray diffraction. [Au{(PPh(2))(2)C(2)B(9)H(10)}(PPh(3))] (1) (dichloromethane solvate) crystallizes in the monoclinic space group P2(1)/c, with a = 17.326(3) Å, b = 20.688(3) Å, c = 13.442(2) Å, beta = 104.710(12) degrees, Z = 4, and T = -100 degrees C. [Au(2){(PPh(2))(2)C(2)B(9)H(10)}(2)(&mgr;-dppp)] (7) (acetone solvate) is triclinic, space group P&onemacr;, a = 13.432(3) Å, b = 18.888(3) Å, c = 20.021(3) Å, alpha = 78.56(2) degrees, beta = 72.02(2) degrees, gamma = 73.31(2) degrees, Z = 2, and T = -100 degrees C. In both complexes the gold atom exhibits trigonal planar geometry with the 7,8-bis(diphenylphosphino)-7,8-dicarba-nido-undecaborate(1-) acting as a chelating ligand.

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