3d Metal Alkynyls for Materials - Tong Ren Group - Purdue Chemistry
Ren Research Group

Area I. 3d Metal Alkynyls for Materials

The chemistry of 3d metal alkynyls supported by polyaza macrocyclic ligands was generally underdeveloped compared to those based on 4d / 5d metals with soft auxiliary ligands. Our recent efforts demonstrated that the trans-[M(cyclam)(C2R)2]+ type (cyclam = 1,4,8,11-tetraazacyclotetradecane) compounds can be readily prepared from reactions between [M(cyclam)Cl2]+ and LiC2R for M = Cr(III), Fe(III), and Co(III). Furthermore, both the trans-[Co(cyclam)(C2R)Cl]+ and {trans-[Co(cyclam)Cl]2(m-(C≡C)n)}2+ type compounds can be prepared through a dehydrohalogenation reaction. The latter compounds provided a chance to assess the electronic coupling across oligoyn-diyls between two M(cyclam) units. Cr(III) centered phosphorescence has been studied for a number of Cr(cyclam') type complexes, where cyclam' represents C-substituted cyclam.

Figure 1

Most recently, the stepwise alkynylation at CoIII(cyclam) center enabled the preparation of the donor-bridge-acceptor (D-B-A) dyads, where the donor is aniline or related arylamine, and the acceptor is N-alkyl-1,8-naphthalimide (NAP). Currently, the evolution of NAP-based excited states in Co-based D-B-A and its modulation through the excitation of Co-bound C≡C bonds are being investigated.

Figure 2

Selected References:

General review: Ren, T. Chem. Commun. 2016, 52, 3271-3279; "A Sustainable Metal Alkynyl Chemistry: 3d Metals and Polyaza Macrocyclic Ligands"; http://dx.doi.org/10.1039/c5cc09365a.

Recent Publications:

Natoli, S. N.; Azbell, T. J.; Fanwick, P. E.; Zeller, M.; Ren, T. Organometallics 2016, 35, 3594-3603; "A Synthetic Approach to Cross-pi-Conjugated Organometallic Systems Based on geminal-Diethynylethene and CoIII(cyclam)"; http://dx.doi.org/10.1021/acs.organomet.6b00657.

Cook, T. D.; Natoli, S. N.; Fanwick, P. E.; Ren, T. Organometallics 2016, 35, 1329-1338; "CoIII(cyclam) Oligoynyls: Monomeric Oligoynyl Complexes  and Dimeric Complexes with an Oligoyn-diyl Bridge"; http://dx.doi.org/10.1021/acs.organomet.6b00219.

Tyler, S. F.; Judkins, E.; Song, Y.; Cao, F.; McMillin, D. R.; Fanwick, P. E.; Ren, T. Inorg. Chem. 2016, 55, 8736-8743; "Cr(III)-HMC (HMC = 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane) Alkynyl Complexes - Preparation and Emission Properties"; http://dx.doi.org/10.1021/acs.inorgchem.6b01285.

Cao, Z.; Forrest, W. P.; Gao, Y.; Fanwick, P. E.; Ren, T. Organometallics 2012, 31, 6199-6206; "trans-[Fe(cyclam)(C2R)2]+: A New Family of Fe(III) Bis-Alkynyl Compounds"; http://dx.doi.org/10.1021/om300515r.