Single crystals of the title compound bis[bis-(1-ethyl-3-methyl-imidazol-2-yl-idene)silver(I)] 1,5,5,7,11,11-hexa-chloro-2,8-di-oxa-4,6,10,12,13,14-hexa-aza-1λ(5),3,5λ(5),7λ(5),9,11λ(5)-hexa-phospha-tricyclo-[7.3.1.1(3,7)]tetra-deca-1(13),4,7(14),10-tetra-ene-6,12-diide 3,9-dioxide, [Ag(C(6)H(10)N(2))(2)](Cl(6)N(6)O(4)P(6))(0.5), were isolated from the reaction of the silver N-heteocyclic carbe...

The complexes IPrMCl (IPr = 1,3-bis(diisopropylphenyl)imidazol-2-ylidene, M = Cu, 1a; M = Au, 1b), in the presence of one equiv of NaBAr'(4) (Ar' = 3,5-bis(trifluoromethyl)phenyl), catalyze the transfer of carbene groups: C(R)CO(2)Et (R = H, Me) from N(2)C(R)CO(2)Et to afford products that depend on the nature of the metal center. The copper-based catalyst yields exclusively a cycloheptatriene ...

We prepared rhodopsin mutants that contained a single reactive cysteine residue per rhodopsin molecule at position 65, 140, 240, or 316 on the cytoplasmic face. A carbene-generating photoactivatable group was linked by a disulfide bond to the cysteine sulfhydryl group of each of the rhodopsin mutants. The resulting derivative was then light-activated at lambda > 495 nm to form the metarhodopsin...

Reaction of [(((Ad)ArO)(3)tacn)U(III)] (1) or [((Me(3)Si)(2)N)(3)U(III)] (3) with tetramethylimidazol-2-ylidene (Me(4)IMC:) yields novel N-heterocyclic carbene complexes [(((Ad)ArO)(3)tacn)U(III)(Me(4)IMC:)] (2) and [((Me(3)Si)(2)N)(3)U(III)(Me(4)IMC:)] (4). Uranium complexes 2 and 4 represent the first examples of compounds with an N-heterocyclic carbene ligand coordinated to a low-valent uran...

Deprotonation of N,N-diisopropyl-C-ferrocenylaldiminium triflate 2 cleanly leads to the corresponding 1,2-diamino-1,2-diferrocenylethene 3, the dimer of the desired (amino)(ferrocenyl)carbene. Fulvene 6, obtained by addition of the lithium salt of tetramethylcyclopentadiene to methoxyformamidinium methylsulfate 5, reacts with dicarbonylcyclopentadienylbromoiron(II), and with a mixture of FeCl(2...

A variety of half-sandwich iron(ii) complexes with diprotic acyclic diaminocarbene ligands (pADCs) have been obtained by reaction of the cationic complexes [Fe(Cp)(CO)2(CNR)]+ and [Fe(Cp)(CO)(CNR)2]+ with methylamine, and their acid-base behaviour was studied, revealing an easy reversible deprotonation reaction of both N-H moieties of the carbene ligands. The deprotonation process is frequently...

The electronic structure of the lowest carbene state of a representative early-transition-metal complex, CrCH2+ (6A1 symmetry), has been examined by using ab initio techniques. Its properties reveal a complex with a single u-donor bond from singlet CH2 to high-spin (d5) Cr+ and no *-back-bond, resulting in a low bond energy (38.7 kcal/mol) and a large carbenealkylidene state splitting (18.8 kca...

[reaction: see text] The promising utility of triazolyl N-heterocyclic carbene catalysts in umpolung aldehyde chemistry requires a straightforward reliable synthesis from readily available materials. Herein, we describe the synthesis of a variety of triazolyl N-heterocyclic carbene precursors. The reactions commence from commercially available amino acids and proceed in 44-68% overall yields. T...

The first thorium poly-carbene complexes [(Ph(2)P=S)(2)C](2)Th(DME) (2) and [{[(Ph(2)P=S)(2)C](3)Th}Li(2)(DME)](n) (3) have been prepared and structurally characterized. DFT calculations reveal that the Th=C bond is polarized toward the nucleophilic carbene carbon atom, which is further verified by the experimental observation that the Th=C bond shows a nucleophilic behavior with Ph(2)CO.

Dimetal complexes of a new N-heterocyclic carbene/phenanthroline ligand have been synthesized. Coordination of both ruthenium and rhenium to the phenanthroline moiety in combination with platinum at the carbene moiety are reported. Steady-state and time-resolved optical absorption and photoluminescence spectra were obtained for the complexes. These results illustrate significant changes occur w...