A mixed valence zinc dithiolene system with spectator metal and reactor ligands

DOI

10.1016/j.poly.2016.01.023

Document Type

Journal Article

Publication Date

8-16-2016

Publication Title

Polyhedron

Volume

114

First Page

370

Last Page

377

ISSN

2775387

Keywords

Dithiolene, Dithione, Donor-acceptor system, Ligand to ligand charge transfer, Zinc

Abstract

Neutral complexes of zinc with N,N′-diisopropylpiperazine-2,3-dithione (iPr2Dt0) and N,N′-dimethylpiperazine-2,3-dithione (Me2Dt0) with chloride or maleonitriledithiolate (mnt2-) as coligands have been synthesized and characterized. The molecular structures of these zinc complexes have been determined using single crystal X-ray diffractometry. Complexes recrystallize in monoclinic P type systems with zinc adopting a distorted tetrahedral geometry. Two zinc complexes with mixed-valence dithiolene ligands exhibit ligand-to-ligand charge transfer bands. Optimized geometries, molecular vibrations and electronic structures of charge-transfer complexes were calculated using density functional theory (B3LYP/6-311G+(d,p) level). Redox orbitals are shown to be almost exclusively ligand in nature, with a HOMO based heavily on the electron-rich maleonitriledithiolate ligand, and a LUMO comprised mostly of the electron-deficient dithione ligand. Charge transfer is thus believed to proceed from dithiolate HOMO to dithione LUMO, showing ligand-to-ligand redox interplay across a d10 metal.

Open Access

Green Accepted

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