Abstract
The reactions of N-heterocyclic carbene Cu(I) and Ag(I) halides with potassium thio- or seleno-cyanate gave unexpected products. The attempted substitution reaction of bromido-(1,3-dibenzyl-4,5-di-phenyl-imidazol-2-yl-idene)silver (NHC*-Ag-Br) with KSCN yielded bis-[bis-(1,3-dibenzyl-4,5-di-phenyl-imidazol-2-yl-idene)silver(I)] tris-(thio-cyanato)-argentate(I) diethyl ether disolvate, [Ag(C(29)H(24)N(2))(2)][Ag(NCS)(3)]·2C(4)H(10)O or [NHC*(2)Ag](2)[Ag(SCN)(3)]·2Et(2)O, (1), while reaction with KSeCN led to bis-(μ-1,3-dibenzyl-4,5-diphenyl-2-seleno-imidazole-κ(2) Se:Se)bis-[bromido-(1,3-dibenzyl-4,5-diphenyl-2-seleno-imid-azole-κSe)silver(I)] di-chloro-methane hexa-solvate, [Ag(2)Br(2)(C(29)H(24)N(2)Se)(4)]·6CH(2)Cl(2) or (NHC*Se)(4)Ag(2)Br(2)·6CH(2)Cl(2), (2), via oxidation of the NHC* fragment to 2-seleno-imidazole. This oxidation was observed again in the reaction of NHC*-Cu-Br with KSeCN, yielding catena-poly[[[(1,3-dibenzyl-4,5-diphenyl-2-seleno-imidazole-κSe)copper(I)]-μ-cyanido-κ(2) C:N] aceto-nitrile monosolvate], {[Cu(CN)(C(29)H(24)N(2)Se)]·C(2)H(3)N} (n) or NHC*Se-CuCN·CH(3)CN, (3). Compound (1) represents an organic/inorganic salt with Ag(I) in a linear coordination in each of the two cations and in a trigonal coordination in the anion, accompanied by diethyl ether solvent mol-ecules. The tri-blade boomerang-shaped complex anion [Ag(SCN)(3)](2-) present in (1) is characterized by X-ray diffraction for the first time. Compound (2) comprises an isolated centrosymmetric mol-ecule with Ag(I) in a distorted tetra-hedral BrSe(3) coordination, together with di-chloro-methane solvent mol-ecules. Compound (3) exhibits a linear polymeric (1) (∞)[Cu-C≡N-Cu-] chain structure with a seleno-imidazole moiety additionally coordinating to each Cu(I) atom, and completed by aceto-nitrile solvent mol-ecules. Electron densities associated with an additional ether solvent mol-ecule in (1) and two additional di-chloro-methane solvent mol-ecules in (2) were removed with the SQUEEZE procedure [Spek (2015 ▸). Acta Cryst. C71, 9-18] in PLATON.