Intra- and intermolecular interactions in a series of chlorido-tricarbonyl-diazabutadienerhenium(I) complexes: structural and theoretical studies

Abstract

A series of new chlorido-tricarbonylrhenium(I) complexes bearing alkyl-substituted diazabutadiene (DAB) ligands, namely N,N′-bis(2,4-dimethylbenzene)-1,4-diazabutadiene (L1), N,N′-bis(2,4-dimethylbenzene)-2,3-dimethyl-1,4-diazabutadiene (L2), N,N′-bis(2,4,6-trimethylbenzene)-2,3-dimethyl-1,4-diazabutadiene (L3) and N,N′-bis(2,6-diisopropylbenzene)-1,4-diazabutadiene (L4), were synthesized and investigated. The crystal structures have been fully characterized by X-ray diffraction and spectroscopic methods. Density functional theory, natural bond orbital and non-covalent interaction index methods have been used to study the optimized geometry in the gas phase and intra- and intermolecular interactions in the complexes, respectively. The most important studied interactions in these metal carbonyl complexes are n→π*, n→σ* and π→π*. Among complexes 1–4, only 2 shows interesting intermolecular n→π* interactions due to lp(C[triple-bond]O)...π* and lp(Cl)...π* (lp = lone pair) contacts.

Supramolecular assembly through intermolecular n → π* interactions through a coordinated perrhenate formed via superoxidation of Re(i) to Re(vii) in the formation of substituted Re(CO)3 complexes bearing Diimine ligands

“…To this effect, the study of metal carbonyls complexes on the basis of participation in a n→π* interaction similar to their organic counterparts and related to their role in catalysis are of considerable interest. Therefore, in a continuation of our interest in intra-and intermolecular n→π* interactions in metal-carbonyl complexes, [27][28][29][30] herein, we report the synthesis, full structural and computational studies of two new Re(CO)3 complexes bearing diimine ligands with a coordinated perrhenate, formed via superoxidation of Re(I), and its potential as supramolecular synthon for assembly through n→π* interactions. Please do not adjust margins Please do not adjust margins the [Re(CO)3(Ph4TAP)] + and [Re(CO)3(Dafone)] + cations to form the neutral di-rhenium mixed oxidation state complexes in good yields (69% for 1 and 70% for 2).…”