Abbas Raja Naziruddin

Photofunctional Platinum Complexes Featuring N‐heterocyclic Carbene‐Based Pincer Ligands

Photoactive platinum complexes of stoichiometry [Pt((R)CCC(R))L](0/+) (R = Me, nBu and L = -CN, -C≡CPh, -N≡CCH3, -Py, -CO) featuring pincer-type bis N-heterocyclic carbene (NHC) ligands ((R)CCC(R)) were synthesized. Organometallic syntheses of these complexes are facile and achievable through standard laboratory procedures. Control of intermolecular Pt⋅⋅⋅Pt interaction, π-π stacking, and emission tuning is achieved through suitable choice of the NHC-wingtip substituent (R) and the auxiliary ligand (L). Exposure to specific volatile organic compounds (VOCs) or mechanical grinding triggers changes in emission colors, which render these complexes photofunctional. Solid-state structures and photoluminescence results are described herein.

Direct C-metallation of N-substituted triazoles promoted by mercury acetate. An alternative route to N-heterocyclic carbene complexes

C-Metallation of neutral mono-substituted triazoles could be induced by Hg(OAc)2 to give a near quantitative yield of C,N-bonded mercury complexes. Initial N-coordination to mercury(II) is confirmed by NMR spectroscopy. Subsequent acetate assisted deprotonation–metallation is a viable route to C-metallated products. Hg(OAc)2 is unique for this reaction. Metal salts of Ag2O, Ag(OAc), Pd(OAc)2 or HgCl2 in combination with bases of NaOH and K2CO3 did not yield triazolate complexes. Further reaction of one of these mercury(II)–C,N-triazolate complexes with a source of methyl cation yielded a monomeric N-heterocyclic carbene complex. Therefore the facile reaction of triazole with Hg(OAc)2 followed by alkylation is a handy alternative way to prepare Hg–NHCs.