Synthesis, structure and properties of tris(1-ethyl-4-isopropyl-imidazolyl-κN)phosphine copper(II)

Abstract

a b s t r a c tIn this study we report the synthesis and characterization of [Cu(T1Et4iPrIP)(CH 3 OH)Cl]Cl (1) (T1Et4iPrIP = tris(1-ethyl-4-isopropyl-imidazolyl)phosphine). T1Et4iPrIP serves as a His 3 biomimetic ligand binding metals through the 3-nitrogen of the imidazolyl group. The structure of 1 features copper(II) bonded to three nitrogen ligands from T1Et4iPrIP along with an oxygen ligand from methanol and a chloride ligand to form slightly distorted square pyramidal geometry with an imidazole group occupying the axial position and the methanol and chloride ligands situated in the basal plane. The weak sigma donation of the ligand set results in low energy d-d electronic transitions and small A k (131 G). Time-dependent DFT calculations (B3LYP, 6-311+G(d,p)) on the optimized structure of 1 in methanol solvent allowed for the assignment of specific electronic transitions in the UV-Vis spectrum. The highest occupied molecular orbital (HOMO) was noted to consist of 65% Cu-d character identified as the d x 2 Ày 2 orbital.

Metal Dependent Formation of Imidazolidine or Hemiaminal Ether Complexes from Multicomponent One‐pot Reactions

“…Triazacyclononane (tacn), cyclohexanetriamine (chta), trithiacyclononane (ttcn), etc., are known as crown ligands. The HC(CH 2 PPh 2 ) 3 (tpddmm), tris(pyrazolyl)methane (tpm), tris(pyridyl)methane (tpym), tris(pyrazolyl)borate (tpb), tris(imidazol‐2‐ylidene)borate (timyb), tris(aminoethyl)alkane (taea), tris(diphenyl‐phosphinomethyl)ethane (tppe), tris(phosphinomethyl)borate (tpmb), tris(imidazolyl)phosphine (tip), tris(diphenylphosphineoxide)methane (tpmo), etc., are scorpionate ligands, whereas diethylenetriamine (dien), dipicolylamine (dpa), koneramine, are linear ribbon type ligands . The crowns and scorpionates strictly coordinate to a metal ion facially ( fac ) whereas the ribbon type ligands are known to undergo both facial or meridional ( mer ) coordination modes according to the size of the metal ions .…”