| Popis: |
The complexes (Ph3P)2Cu(carboxylate) (carboxylate = acetate (1), hippurate (2), vinyl acetate (3), fluorenate (4)) have been prepared and their solid-state structures determined crystallographically. The copper(I) center in all four structures exhibits a distorted tetrahedral geometry, with varying degrees of asymmetric bidentate binding of the carboxylate ligand. For example, in complex 2 the hippurate ligand displays the greatest extent of asymmetry with the two CuO bond distances differing by 0.234(6) A. The structures of all four derivatives were each shown to be the same both in the solid-state and in dichloromethane solution based on infrared spectroscopy. The magnitude of Δ (va(CO2−)-vs(CO2−)) in these copper(I) derivatives, determined to be quite similar to the corresponding ionic values, is used as constituting a diagnosis for asymmetric bidentate binding of the carboxylate ligand. Although all four complexes are structurally quite similar, only the fluorenate derivative which affords a resonance-stabilized carbanion upon carbon dioxide extrusion undergoes the decarboxylation reaction. Crystal data for 1: space group P21/c, a = 18.085(5), b = 10.977(2), c = 17.979(5) A, β = 115.62(2)°, Z= 4, R =3.91%. Crystal data for 2: space group P1, a = 9.96(2), b = 14.68(3), c = 14.96(3) A , a = 115.46(14), β = 97.54(16), η = 102.31(15)°, Z = 2, R=5.84%. Crystal data for 3: space group P1, a = 12.755(3), b = 13.125(2), c = 12.572(2) A, α = 118.85(1), β = 105.85(1), η = 97.65(1)°, Z = 2, R =4.08%. Crystal data for 4: space group P1, a = 11.554(1), b = 15.217(2), c = 15.285(2) A, α = 63.71(1), β = 79.08(1), η = 75.20(1)°, Z = 2, R = 7.6%. |
