The nitrogen oxides NO 2 ,NO, and N 2 Oare among the most potent air pollutants of the 21 st century.Abimetallic Rh I -Pt II complex containing an especially designed multidentate phosphine olefin ligand is capable of catalytically detoxifying these nitrogen oxides in the presence of hydrogen to form water and dinitrogen as benign products.The catalytic reactions were performed at room temperature and low pressures (3-4 bar for combined nitrogen oxides and hydrogen gases). Aturnover number (TON) of 587 for the reduction of nitrous oxide (N 2 O) to water and N 2 was recorded, making these Rh I -Pt II complexes the best homogeneous catalysts for this reaction to date.L ower TONs were achieved in the conversion of nitric oxide (NO,TON = 38) or nitrogen dioxide (NO 2 ,T ON of 8). These unprecedented homogeneously catalyzedh ydrogenation reactions of NO x were investigated by ac ombination of multinuclear NMR techniques and DFT calculations,w hich provide insight into ap ossible reaction mechanism. The hydrogenation of NO 2 proceeds stepwise,t o first give NO and H 2 O, followed by the generation of N 2 Oand H 2 O, whichi st hen further converted to N 2 and H 2 O. The nitrogen À nitrogen bond-forming step takes place in the conversion from NO to N 2 Oa nd involves reductive dimerization of NO at ar hodium center to give ah yponitrite (N 2 O 2 2À ) complex, whichw as detected as an intermediate.

Addition ofthe PÀ H bond in bis(mesitoyl)phosphine, HP(COMes) 2 (BAPH), to a wide variety of activated carbon-carbon double bonds as acceptors was investigated. While this phospha-Michael addition does not proceed in the absence of an additive or catalyst, excellent results were obtained with stoichiometric basic potassium or caesium salts. Simple amine bases can be employed in catalytic amounts, and tetramethylguanidine (TMG) in particular is an outstanding catalyst that allows the preparation of bis(acyl)phosphines, RÀ P(COMes) 2 , under very mild conditions in excellent yields after only a short time. All phosphines RP(COMes) 2 can subsequently be oxidized to the corresponding bis(acyl)phosphane oxides, RPO(COMes) 2 , a substance class belonging to the most potent photoinitiators for radical polymerizations known to date. Thus, a simple and highly atom economic method has been found that allows the preparation of a broad range of photoinitiators adapted to their specific field of application even on a large scale.

The dehydrogenation of organosilanes (RxSiH4−x) under the formation of Si−Si bonds is an intensively investigated process leading to oligo‐ or polysilanes. The reverse reaction is little studied. To date, the hydrogenolysis of Si−Si bonds requires very harsh conditions and is very unselective, leading to multiple side products. Herein, we describe a new catalytic hydrogenation of oligo‐ and polysilanes that is highly selective and proceeds under mild conditions. New low‐valent nickel hydride complexes are used as catalysts and secondary silanes, RR′SiH2, are obtained as products in high purity.

The dehydrogenation of organosilanes (RxSiH4−x) under the formation of Si−Si bonds is an intensively investigated process leading to oligo‐ or polysilanes. The reverse reaction is little studied. To date, the hydrogenolysis of Si−Si bonds requires very harsh conditions and is very unselective, leading to multiple side products. Herein, we describe a new catalytic hydrogenation of oligo‐ and polysilanes that is highly selective and proceeds under mild conditions. New low‐valent nickel hydride complexes are used as catalysts and secondary silanes, RR′SiH2, are obtained as products in high purity.

The nitrogen oxides NO 2 ,NO, and N 2 Oare among the most potent air pollutants of the 21 st century.Abimetallic Rh I -Pt II complex containing an especially designed multidentate phosphine olefin ligand is capable of catalytically detoxifying these nitrogen oxides in the presence of hydrogen to form water and dinitrogen as benign products.The catalytic reactions were performed at room temperature and low pressures (3-4 bar for combined nitrogen oxides and hydrogen gases). Aturnover number (TON) of 587 for the reduction of nitrous oxide (N 2 O) to water and N 2 was recorded, making these Rh I -Pt II complexes the best homogeneous catalysts for this reaction to date.L ower TONs were achieved in the conversion of nitric oxide (NO,TON = 38) or nitrogen dioxide (NO 2 ,T ON of 8). These unprecedented homogeneously catalyzedh ydrogenation reactions of NO x were investigated by ac ombination of multinuclear NMR techniques and DFT calculations,w hich provide insight into ap ossible reaction mechanism. The hydrogenation of NO 2 proceeds stepwise,t o first give NO and H 2 O, followed by the generation of N 2 Oand H 2 O, whichi st hen further converted to N 2 and H 2 O. The nitrogen À nitrogen bond-forming step takes place in the conversion from NO to N 2 Oa nd involves reductive dimerization of NO at ar hodium center to give ah yponitrite (N 2 O 2 2À ) complex, whichw as detected as an intermediate.