The Co(cyclam) (cyclam = 1,4,8,11-tetraazacyclotetradecane) has been shown to catalyze reduction of CO2, and functionalization with one alkynyl ligand provides an opportunity to attach the catalyst to an electrode or solid support for heterogeneous catalysis, or a photosensitizer for photocatalysis.  Stepwise functionalization with a second equivalent of the alkyne allows for controlled preparation of �wire-like� molecules which have been shown to facilitate electron transfer across a long distance. Reported herein are the syntheses and characterization of both mono- and bis-alkynyl complexes of [CoIII(cyclam)]. Treatment of trans-[Co(cyclam)Cl2]Cl with excess LiC2R (R = TMS, C2TMS, C6H5, C6H4SCH2CH2TMS) resulted in formation of [Co(cyclam)(C2R)2]Cl in good yield, while treatment with Et3N and 1 equivalent of HC2R yielded exclusively the mono-alkynyl derivative.  Asymmetric complexes bearing two different alkynyl ligands were also prepared by treatment of [Co(cyclam)(C2R)Cl]Cl with a slight excess of LiC2R'.  Complexes were analyzed by mass spectrometry; UV-Vis, FT-IR, and NMR spectroscopy; cyclic voltammetry and Xray crystallography to gain insight into their molecular and electronic structures.

Symmetric and unsymmetric s-alkynyl complexes with a [Co(cyclam)]<sup>3+ </sup>core

246th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.

Symmetric and unsymmetric s-alkynyl complexes with a [Co(cyclam)]3+ core

Symmetric and unsymmetric s-alkynyl complexes with a [Co(cyclam)]³⁺core