Octahedral tungsten iodide clusters equipped with apical ligands (L) are synthesized to implement substantial photophysical properties. The [WI(CFCOO)] cluster reported herein is the first example of a family of ligand substituted [WIL] clusters. Such compounds are expected to exhibit a rich photochemistry in which the apical ligands play a crucial role. The versatile solid state and solution phase photophysical properties of (TBA)[WI(CFCOO)] described herein parallel characteristics obtained in some photophysically active organic compounds, including a broad absorption in the UV/VIS region. Upon irradiation of this compound, a broad red emission is observed in the VIS/NIR region resulting from excited triplet states, and singlet oxygen (aΔ) is generated in the presence of O.
The in situ generated CNC pincer lithium complex [Li(bimca)] (2) (bimca = bis(3-methylimidazolin-2ylidene)carbazolide) reacts with M = Pt(0), Pd(0), and Ni(0) precursors under formal oxidative addition to (bimca)hydrido M(II) complexes 3. This unusual reaction involves proton abstraction that can derive from various sources including the ligand itself. Mechanistic considerations are given. The respective [M(bmica)Cl] complexes 4 have been prepared from the hydrido complexes 3 and subjected to reduction in order to identify a proposed zerovalent anionic [M(bimca)] − complex. In the case of M = Pt, only the (bimca)hydrido Pt(II) complex is observed, whereas, for [Pd(bimca)Cl], a dimeric Pd(0) complex [Pd 2 (bimca) 2 ]K 2 (6) bearing an anionic carbazole moiety is formed in the solid state. NMR DOSY experiments show that, in solution, this dimer dissociates to the monomeric anionic complex [Pd(bimca)] − (5b). We conclude that such anionic zerovalent complexes are plausible intermediates in the synthesis of group 10 metal(II) complexes from the respective metal(0) species with anionic CNC ligands.
Synthesis of a new example of the pyridazine annelated bis(N-heterocyclic carbene) ligand 3b (vegi) bearing benzyl substituents is reported, as well as the synthesis of its cationic Rh(cod) complex 5b. The mechanism of formation of the [Rh(cod)(vegi)] + complexes was investigated, showing a stepwise deprotonation of the imidazolium moieties via the mono-carbene imidazolium Rh(cod)Cl species 4. The [Rh-(cod)(vegi)] + complexes 5a,b show catalytic activity in the transfer hydrogenation of even sterically hindered ketones.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.