Metal derivatives of azoles. Part VII. Gold(I) derivatives of pyrazoles

Abstract

Introduction During our investigation in the field of pyrazolel complexes and of pyrazolates, several gold derivatives of the pyrazolato anion were obtained, including the tri-, di-, and mononuclear species A, B, and C, where the ligand is either bi-or monodentate (I). The first type of compound, A, was obtained, inter alia , through reaction [I]

Reactivity of phosphido-bridged diplatinum complexes towards electrophiles: synthesis of new hydrides and related Pt2Cu and Pt2Ag clustersDedicated to Prof. D. Fenske on the occasion of his 60th birthday, with our most sincere congratulations and best wishes.

“…1 Amongst them, the hydrido complexes constitute a large family, with diversified structural and spectroscopic features. [2][3][4] The Pt atoms are often linked through metal-metal bonding and/or hydrido bridges. A bridging hydride may also be associated with another, chemically different bridging unit.…”

Structure of [3,5-(C6H5)2C3H2N2]4. A 3,5-diphenylpyrazole tetramer linked by hydrogen bonds

“…The suggestion that pyrazole and 3,5-dimethylpyrazole form stable hydrogen-bonded trimers (Anderson, Duncan & Rossotti, 1961) gave birth to the idea that replacing the bridging hydrogens with two-coordinate metal atoms would generate trimeric metallocyclic complexes. This idea was successfully explored (Bonati, Minghetti & Banditelli, 1974) and several complexes of the general formula [Au(~-3,5-R2pz)]3 were prepared (Banditelli, Bandini, Minghetti & Bonati, 1981;Banditelli, Bandini, Bonati, Goel & Minghetti, 1982). In the case of R = CF3, a crystallographic study confirmed the expected trimeric structure (Bovio, Bonati & Banditelli, 1984).…”

C–H and N–H activation by Pt(0) in N- and O-heteroaromatic compounds

“…Three phosphine resonances were also present in the 31 P NMR spectrum: d 1 23.63 ppm, d, J P;P ¼ 33.1 Hz, J P;P ¼ 2.5 Hz; 2 J Pt;P ¼ 488 Hz, 1 J Pt;P ¼ 4705 Hz; d 2 3.40 ppm, J P;P ¼ 24.2 Hz, J P;P ¼ 2.5 Hz, 2 J Pt;P ¼ 96 Hz, 1 J Pt;P ¼ 2458 Hz; d 3 1.95, J P;P ¼ 24.2 Hz, J P;P ¼ 33.1 Hz, 2 J Pt;P ¼ 120 Hz, 1 J Pt;P ¼ 2411 Hz ( 2 J Pt;P values are generally considerably smaller than 1 J Pt;P values [45]). These data indicate that a bridging phosphido group is not present as such groups resonate far downfield (>100 ppm) [46].…”