Novel triangulo copper(I) complexes containing mu(3)-eta(1)-alkynyl, mu(3)-chloride, and mu-eta(1)-ioscyanide ligands: X-ray crystal structure of [Cu-3(mu(3)-eta(1)-C CC6H4CH3-4) (mu-eta(1)-C NC6H4CH3-4)(mu-dppm)3][BF4](2)center dot 3CH(2)Cl(2)

Trinuclear copper(I) isocyanide complexes [Cu-3(mu(3)-eta(1)-C=CR1)mu-eta(1)-C=NR2)mu-dppm)(3)][BF4](2) (dppm=bis(diphenylphosphino)methane; R-1=C6H5, R-2=CH2C6H5 (1), C6H11 (2), 4-CH3C6H4 (3); R-1 = 4-CH3C6H4, R-2=CH2C6H5 (4), C6H11 (5), 4-CH3C6H4 (6))have been prepared by reaction of the complexes [Cu-3(mu(3)-eta(1)-C=CR1)(mu-dppm)(3)][BF4](2) with isocyanides in CH2Cl2 at room temperature. Similarly, the treatment of the complex [Cu-3(mu(3)-Cl)(2)(mu-dppm>(3)][BF4] with isocyanides in CH2Cl2 and in the presence of AgBF4 affords the complexes [Cu-3(mu(3)-Cl)(mu-eta(1)-C=NR)(mu-dppm)(3)][BF4](2) (R=CH2C6H5 (7), C6H11 (8), 4-CH3C6H4 (9)) Crystal structure of the complex 6 has been determined by X-ray diffraction methods. The cationic complex consists of a scalene triangle arrangement of the copper atoms bridged by three dppm Ligands, with the p-tolyl isocyanide ligand bridging the shortest edge and the p-tolylethynyl ligand showing an asymmetric mu(3)-eta(1) bridging mode. The isocyanide group shows an unusual linearity (C-N-C=171.13(9)degrees). H-1 and P-31{H-1} NMR data are also reported. Variable-temperature P-31{H-1} NMR studies reveal a dynamic behavior of the isocyanide ligand in solution on the basis of a mu-eta(1) to mu(3)-eta(1) isocyanide exchange process.