A DICYANOARGENTATE(I) ROD BEHAVING AS A DISCRETE ANION, A MONODENTATE SHAFT OR SHANK, AND AN AMBIDENTATE SHAFT IN THE CRYSTAL STRUCTURES OF IMIDAZOLE-BLADE LIGATED CADMIUM(II) DICYANOARGENTATE(I) COMPLEXES - TRANS-BIS[DICYANOARGENTATO(I)]TETRAKIS(IMI

摘要

The crystal structures of four [dicyanoargentato(I)]cadmium(II) complexes with the mixed ligation of imidazole (imH: C3H4N2) or N-methyl- or 2-methylimidazole (N-Meim or 2-MeimH: C3H6N2) On the cadmium(II), [Cd(imH)(4){Ag(CN)(2)}(2)] (1a), [Cd(imH)(5){Ag(CN)(2)}][Ag(CN)(2)] (1b), [Cd(N-Meim)(4){Ag(CN)(2)}][Ag(CN)(2)] (2), and [Cd(2-MeimH)(4){Ag(CN)(2)}][Ag(CN)(2)]. H2O (3), have been determined by single-crystal X-ray diffraction methods. Complex la crystallizes in the orthorhombic Pbmn space group with a = 22.206(2) Angstrom, b = 10.306(1) Angstrom, c = 10.318(1) Angstrom, Z = 4. 1b: monoclinic P2(1), a = 9.028(4) Angstrom, b = 13.988(6) Angstrom, c = 22.079(4) Angstrom, beta = 101.02(2)degrees, Z = 4. 2: monoclinic C2/m, a = 11.1292(8) Angstrom, b = 11.435(3) Angstrom, c = 11.266(1) Angstrom, beta = 94.252(8)degrees, Z = 2. 3: orthorhombic Pnnm, a = 11.212(2) Angstrom, b = 11.156(5) Angstrom, c = 23.646(5) Angstrom, Z = 4. Complex la has the shape of a four-blade propeller consisting of [Cd(imH)(4)](2+) with the shaft being the monodentate [-NCAgCN](-) anions. 1b comprises the discrete [Ag(CN)(2)](-) and the umbrella-shaped [Cd(imH)(5)NCAgCN](+) in which the monodentate [Ag(CN)(2)](-) behaves as the shank; hydrogen-bond networks among the umbrellas build up a three-dimensional lattice. In 2 and 3 the four-blade propellers of [Cd(N-Meim)(4)](2+) and [Cd(2-MeimH)(4)](2+) are successively linked at every Cd by the ambidentate -NCAgCN- rods to form an infinite chain, respectively; the discrete [Ag(CN)(2)](-) anions and the H2O in 3 are accommodated in the interchain space. The varieties in coordination behavior of [Ag(CN)(2)](-) can be interpreted in terms of the hydrogen-bond formation between a pyrrole H of the imidazole ligand and an unbridged N-end of [Ag(CN)(2)](-). [References: 20]