Electrochemical Synthesis of Tricyanomethyl Copper Complexes

Abstract

The synthesis of tricyanomethyl copper complexes has been achieved by anodic dissolution of a sacrificial copper metal and cathodic reduction of 1,1,3,3-tetracyanopropane in acetonitrile, in the presence of triphenylphosphane used as coligand. The electrogenerated tetracyanopropyl radical anion is not stable and undergoes a cleavage leading to the tricyanomethyl anion and acrylonitrile which is electropolymerized at the cathode. The reaction solution gives a neutral dimeric binuclear copper(I) complex, bis{(µtricyanomethanido)bis(triphenylphosphane)copper(I)}[Cu(µ-

Rare, Hexatomic, Boat-Shaped, Cross-Linked Bis(iminodiphenylphosphorano)methanediide Pincer Carbon Bridged Photoluminescent Copper Clusters Capped with Methyl or Halide Bridges

“…Two heterocyclic four-membered rings (Cu(1)C(1)P(1)N(1) and Cu(2)C(1)P(2)N(2)) are connected through the two side borders of the three-membered ring (Cu(1)Cu(2)C(1)), and one points up and one points down relative to the plane of the three-membered ring, forming a chair conformation. The Cu−N (Cu(1)−N(1) = 2.142(3), Cu(2)−N(2) = 2.126(3) Å) and Cu−P lengths (Cu(1)−P(3) = 2.1608(9), Cu(2)−P(4) = 2.1582(9) Å) are in the expected range (e.g., Cu−N = 2.058(2)−2.074(2) Å and Cu−P = 2.1756(7) Å in [{CH(PPh 2 NSiMe 3 ) 2 }CuPPh 3 ] and Cu−N = 2.116(7) and 2.121(6) Å and Cu−P = 2.244(2) Å in cis -[Cu 2 (μ-CN)(Phen)(PPh 3 ) 2 ] 2 [C(CN) 3 ]·BF 4 ·2CH 3 CN). The Cu−C bond distances (Cu(1)−C(1) = 2.031(3) Å and Cu(2)−C(1) = 2.045(3) Å) in 6 are remarkably longer than that in the dicoordinate copper structure (e.g., 1.916(2) Å in [Cy 3 PCuCH 3 ]) and even longer than these in the tricoordinate structures (e.g., Cu−C = 1.921(3) Å in [Cu(CN)(dppm)] and Cu−C = 1.931(5) Å in [Cu(CN)(PCy 3 )] 6 ).…”

Reactions of Potassium Bis(phosphinimino)methanide with Group 11 Compounds

“…A six-membered metallacycle (N1−P1−C1−P2−N2−Cu) is formed by chelation of the two trimethylsilylimine groups to the copper atom, resulting in a twist boat conformation in which the central carbon atom (C1) and the copper atom are displaced from the N 2 P 2 least-squares plane. The Cu−N and Cu−P bond distances are in the expected range of Cu−N1 (2.074(2) Å), Cu−N2 (2.058(2) Å), and Cu−P3 (2.1756(7) Å) (e.g., Cu−N1 = 2.121(6) Å and 2.116(7) Å, and Cu−P = 2.244(2) Å in cis -[Cu 2 (μ-CN)(Phen) 2 (PPh 3 ) 2 ] 2 [C(CN) 3 ]·BF 4 ·2CH 3 CN (phen = 1,10 phenanthroline)) . The distance between the C1 and the copper atom (2.838(3) Å) is remarkably longer than the usual Cu−C distances (e.g., 1.916(2) Å in [Cy 3 PCuMe]); however, a tridentate coordination of the ligand is found, as in earlier observations. − Compared to the starting material, one of the triphenylphosphine groups is detached from the copper atom in the final product.…”

The use of sacrificial anodes for the electrochemical synthesis of metallic complexes

“…In this case, the formation of a triazole ring in the new ligand was proposed to start with a nucleophilic attack of a thioamide nitrogen to the imine carbon, followed by the addition of an acetamide moiety (possibly the result of the copper catalyzed hydrolysis of acetonitrile) [335] and the formation of a new N-S bond which is attributable to the coordination of the metal followed by a reductive elimination [336]. [305]. The crystal data presented for this compound were found identical to those previously reported by Bessler et al [340].…”