New Cu(I)-Ethylene Complexes Based on Tridentate Imine Ligands: Synthesis and Structure

Abstract

A new bulky facially coordinating N3-donor tach-based ligand (tach: cis,cis-1,3,5-triaminocyclohexane) [1: cis,cis-1,3,5-tris(2-fluoro-6-(trifluoromethyl)benzylideneamino)cyclohexane] has been obtained from the condensation of tach with 3 equiv of the appropriate benzaldehyde. Reaction of 1 with [Cu(NCMe)4][PF6] gave the complex [(1)Cu(NCMe)][PF6]. Displacement of the acetonitrile ligand is possible with CO and C2H4 (3-5 bar). Cu(I)-ethylene complexes of ligands 1 and 2 [2: cis,cis-1,3,5-(mesitylideneamino)cyclohexane] were prepared successfully by treatment of the ligands with CuBr and AgSbF6 in the presence of ethylene. These complexes display reversible complexation of the ethylene molecule under mild changes to pressure, suggesting possible application in olefin separation and extraction.

CuIX (X = Cl−, Br−, I−) inorganic networks separated and stabilized by a mercaptotetrazole ligand

“…The Cl3-Cu3-S1, 127.48(10)°; Cl3-Cu3-Cl3C, 121.80(12)°; S1-Cu3-Cl3C, 110.59(9)°, indicating a distorted trigonal geometry. In 1, the Cu-S, Cu-Cl and Cu-N bond lengths are basically consistent with that in other complexes [27][28][29][30][31].…”

Tetrahedral Copper(II) Complexes with a Labile Coordination Site Supported by a Tris-tetramethylguanidinato Ligand

“…First of all, we attempted to get a mononuclear copper­(I) complex using TMG 3 tach, since the ligand might be suited to stabilize a metal complex with a four-coordinate tetrahedral geometry as seen in the reported tach-based ligand systems. ,,,, However, treatment of TMG 3 tach with [Cu I (MeCN) 4 ]­(OTf) in any copper­(I)/ligand ratio always gave the trinuclear copper­(I) complex [Cu I 3 (TMG 3 tach) 2 ]­(OTf) 3 ( 1 ) as confirmed by the elemental analysis and ESI-MS (see Experimental Section). A relatively simple 1 H NMR spectrum of 1 (Experimental Section) suggested that the trinuclear copper­(I) complex has a C 3 symmetry as illustrated in Scheme , where each copper­(I) ion takes a linear two-coordinate structure ligated by two TMG donor groups from different ligands.…”

“…In this study, we present a new N 3 -tridentate ligand, TMG 3 tach, consisting of a rigid cis,cis -1,3,5-triaminocyclohexane (tach) framework and three TMG ( N,N,N ′ N ′-tetramethylguanidino) donor groups (Scheme ). This tach derivative was acquired to construct transition metal complexes with a tetrahedral geometry to mimic reaction centers with a tetrahedral coordination environment for biological small molecule activation. − The TMG group has attracted much recent attention as a strongly electron-donating group in coordination chemistry. − Notable recent examples are the successful generation and characterization of Cu, Fe, and Ni complexes of active oxygen species (superoxide, peroxide, and oxide), relevant to reactive intermediates in biological oxidation/oxygenation chemistry. − Steric effects of the N -alkyl groups on the electron donor ability of the guanidino group have also been examined by changing the N -methyl groups to larger alkyl groups. ,− In addition, TMG-containing aromatic compounds have been developed as noninnocent ligands, to study the electronic communication between the supported transition metal ions and extended π-conjugation systems, consisting of an aromatic ring and the attached guanidino substituents. − …”

Trapping One Electron between Three Beryllium Atoms: Very Strong One‐Electron Three‐Center Bonds

“…[21] For instance, anion sponges containing two BeX substituents decrease their efficiency on going from naphthalenet of luorenet ob iphenyl. [7][8][9] Similarly,f or three BeX-substituteds tructures, 1,3,5-trisubstitutedc yclohexanes (in some cases, the related adamantanes,s ee Figure 1) should be good electron catchers.A nalogous examples are found in the literature such as diphenylphosphinomethyl ligands; [22] imine ligands, [23] tris-(thio)ureas, [24] and methanothiol ligands. [25] To build up tridentate scaffolds of C 3v symmetry,t he framework must have 3o r6Ca toms, which can be conveniently replaced by Oa nd Na toms.…”