title: Cr(III)-HMC (HMC = 5,5,7,12,12,14-Hexamethyl-1,4,8,11-tetraazacyclotetradecane) Alkynyl Complexes: Preparation and Emission Properties.
abstract: Presented here is the chemistry of Cr(III) alkynyl complexes based on the rac-HMC and meso-HMC ligands (HMC = 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane). Thus far, two pairs of cis/trans-[Cr(rac/meso-HMC)(C2R)2]Cl (R = Ph, C2H/C2SiMe3) complexes have been synthesized from reactions between cis/trans-[Cr(rac/meso-HMC)Cl2]Cl and LiC2R. These complexes were characterized using single crystal X-ray diffraction, UV-vis spectroscopy, FT-IR spectroscopy, and fluorimetry. Single crystal X-ray diffraction studies revealed that these complexes adopt a pseudo-octahedral geometry. The electronic spectra of both the cis- and trans-[Cr(rac/meso-HMC)(C4R')2]Cl (R' = H or SiMe3) complexes exhibit d-d bands with pronounced vibronic progression associated with the asymmetric stretch of the Cr-bound C≡C bonds. All of these complexes are phosphorescent and show structured emissions originating from the ligand field excited states.
authors.affiliation: Department of Chemistry, Purdue University , West Lafayette, Indiana 47907, United States.
authors.forename: Sarah F
authors.initials: SF
authors.lastname: Tyler
authors.affiliation: Department of Chemistry, Purdue University , West Lafayette, Indiana 47907, United States.
authors.forename: Eileen C
authors.initials: EC
authors.lastname: Judkins
authors.affiliation: School of Chemistry and Chemical Engineering, Nanjing University , Nanjing 210093, China.
authors.forename: You
authors.initials: Y
authors.lastname: Song
authors.affiliation: School of Chemistry and Chemical Engineering, Nanjing University , Nanjing 210093, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Cao
authors.affiliation: Department of Chemistry, Purdue University , West Lafayette, Indiana 47907, United States.
authors.forename: David R
authors.initials: DR
authors.lastname: McMillin
authors.affiliation: Department of Chemistry, Purdue University , West Lafayette, Indiana 47907, United States.
authors.forename: Phillip E
authors.initials: PE
authors.lastname: Fanwick
authors.affiliation: Department of Chemistry, Purdue University , West Lafayette, Indiana 47907, United States.
authors.forename: Tong
authors.initials: T
authors.lastname: Ren