Rare proximity enforced copper hydrogen interactions in copper(i)-chalcogenones

Copper(i) chalcogenones with rare CuMIDLINE HORIZONTAL ELLIPSISH-C(sp(3)) hydrogen bonding interactions have been reported. The copper(i) bis(benzimidazole-2-chalcogenone) complexes [Cu(L-1)(4)]+BF4- (1) and [Cu(L-2)(4)]+BF4- (2) (L-1 = bis(1-isopropyl-benzimidazole-2-selone)-3-ethyl; L-2 = bis(1-isopropyl-benzimidazole-2-thione)-3-ethyl) have been synthesized and characterized. Both complexes possess distorted tetrahedral geometry with a semi-trans arrangement of the benzimidazole-chalcogenone ligands around the Cu(i) center. The structures of 1 and 2 reveal homoleptic coordination with the Cu(i) center with the (sp(3))C-H groups of the ethylene linker directed towards the Cu(i) center to maximize the rare proximity-enforced intramolecular CuMIDLINE HORIZONTAL ELLIPSISH-C interactions. The CuMIDLINE HORIZONTAL ELLIPSISH-C interactions are found to have a hydrogen bonding nature in the crystalline state, as these interactions are absent in the solution state.

Automated summary

Copper(i) chalcogenones with rare CuMIDLINE HORIZONTAL ELLIPSISH-C(sp(3)) hydrogen bonding interactions have been reported. The synthesized copper(i) bis(benzimidazole-2-chalcogenone) complexes exhibit distorted tetrahedral geometry with rare proximity-enforced intramolecular CuMIDLINE HORIZONTAL ELLIPSISH-C interactions. These interactions show a hydrogen bonding nature in the crystalline state.