The combination of iron salts and N-heterocyclic carbene (NHC) ligands is a highly effective combination in catalysis, with observed catalytic activities being highly dependent on the nature of the NHC ligand. Detailed spectroscopic and electronic structure studies have been performed on both three- and four-coordinate iron(II)-NHC complexes using a combined magnetic circular dichroism (MCD) an...

Quantum chemical calculations of the compound B2(NHC )2 and a thorough examination of the electronic structure with an energy decomposition analysis provide strong evidence for the appearance of boron–boron triple bond character. This holds for the model compound and for the isolated diboryne B2(NHC )2 of Braunschweig which has an even slightly shorter B–B bond. The bonding situation in the mol...

Gold(I) complexes bearing N-heterocyclic carbenes (NHC) of the type (NHC)AuBr (3a/3b) [NHC = 1-methyl-3-benzylimidazol-2-ylidene (= MeBnIm), and 1,3-dibenzylimidazol-2-ylidene (= Bn(2)Im)] are prepared by transmetallation reactions of (tht)AuBr (tht = tetrahydrothiophene) and (NHC)AgBr (2a/2b). The homoleptic, ionic complexes [(NHC)(2)Au]Br (6a/6b) are synthesized by the reaction with free carb...

Reactions of imidazoliums with palladacycles afforded NHC-palladacycle complexes. The reactivity of the NHC-palladacycles was explored and the results demonstrated that they could be template-directed ortho-aromatic metaloxylated in the presence of tert-butyl hydroperoxide (TBHP), affording (NHC)Pd(salicylaldimine)Cl complexes. Furthermore, the NHC-palladacycles showed efficient catalytic activ...

N-Heterocyclic carbenes (NHCs) have emerged as a new class of ligands for materials chemistry that appears particularly relevant for the stabilization and functionalization of metal nanoparticles (NPs). The particular properties and high synthetic flexibility of NHCs make them highly attractive tools for the development of new (nano)materials and the fundamental study of their properties. The r...

Nonhydrolyzable organic carbon (NHC) and sorption isotherms of phenanthrene (Phen) on six size-fractionated NHC fractions in two sediments from the Pearl River and Estuary, South China, were investigated. It was found that NHC including ancient organic carbon, black carbon, resistant aquatic organic carbon, and aged soil organic carbon consists mainly of aliphatic and aromatic carbon using 13C ...

The general synthesis of [Ni(Cp)(X)(NHC)] complexes from a nickel halide, CpLi, and a carbene solution is reported. This procedure yields unprecedented complexes with ring-expanded NHC ligands (RE-NHC) of six- (1a, 1b), seven- (1c), and eight-membered (1d) heterocycles. The NMR spectra of 1a-1d are consistent with the hindered rotation of Ni-Ccarbene and N-CMes bonds, while X-ray analyses of 1b...

Highly selective, narcissistic self-sorting has been observed in the one-pot synthesis of three organometallic molecular cylinders of type [M3 {L-(NHC)3 }2 ](PF6 )3 (M=Ag+ , Au+ ; L=1,3,5-benzene, triphenylamine, or 1,3,5-triphenylbenzene) from L-(NHC)3 and silver(I) or gold(I) ions. The molecular cylinders contain only one type of tris-NHC ligand with no crossover products detectable. Transmet...

The new phosphaalkenyl(chloro)tin(II) compound NHC-Sn(Cl)[C(SiMe3)=PMes*] was isolated and fully characterized including molecular structure determination by a single crystal X-ray diffraction analysis. Its reaction with Me2SAuCl led to the formation of an unprecedented P=C-bridged trinuclear gold complex [AuC(SiMe3)=PMes*]3 through the transfer of the phosphaalkenyl substituent to the gold atom.

Self-compiling implementations of Haskell, i.e., those written in Haskell, have been and, except one, are still space consuming monsters. Object code size for the compilers themselves are 3-8 Mbyte, and they need 12-20 Mbyte to recompile themselves. One reason for the huge demands for memory is that the main goal for these compilers is to produce fast code. However, the compiler described in th...