Konrad Herbst

Koordinationschemie funktioneller Phosphane VIII. Tetracarbonylkomplexe des Wolframs und Molybdäns mit 2-(Diphenylphosphanyl)anilin-Liganden

Abstract The chelate complexes [W(CO) 4 (2-Ph 2 PC 6 H 4 N(R)R′)] (R=R′=H: 1 ; R=H, R′=Me: 2 ; R=R′=Me: 3 ) and [Mo(CO) 4 (2-Ph 2 PC 6 H 4 NMe 2 )] ( 4 ) were prepared and characterized by X-ray structure analysis. Treatment of 1 and 2 with [H(OEt 2 ) 2 ][B{3,5-C 6 H 3 (CF 3 ) 2 } 4 ] provided seven-coordinate ionic tungsten hydrides [WH(CO) 4 (2-Ph 2 PC 6 H 4 NH 2 )][B{3,5-C 6 H 3 (CF 3 ) 2 } 4 ] ( 5 ) and [WH(CO) 4 (2-Ph 2 PC 6 H 4 N(H)Me)][B{3,5-C 6 H 3 (CF 3 ) 2 } 4 ] ( 6 ). Compounds 3 and 4 reacted with NO[BF 4 ] to form [M(CO) 3 (NO)(2-Ph 2 PC 6 H 4 NMe 2 )][BF 4 ] ( 7 ) for M=W but [M(CO) 2 (NO)(2-Ph 2 PC 6 H 4 NMe 2 )FBF 3 ] ( 8 ) for M=Mo.

Funktionelle Phosphane ☆: Part X. Die homogene Hydrierung von Ketonen und α,β-ungesättigten Carbonylverbindungen mit 2-(Diphenylphosphanyl)anilido-Komplexen des Iridiums und Rhodiums als Katalysatoren. Molekülstrukturen von [Rh(PPh3)2(2-Ph2PC6H4NH-κN,κP)] und [Ir(CO)(PPh3)(2-Ph2PC6H4NH-κN,κP)]

Abstract The catalytic hydrogenation of saturated and unsaturated ketones and aldehydes in the presence of [Ir(CO)(PPh 3 )(2-Ph 2 PC 6 H 4 NR-κ N ,κ P )] (R=H: 1 ; R=Me: 2 ), [Rh(CO)(PPh 3 )(2-Ph 2 PC 6 H 4 NR-κ N ,κ P )] (R=H: 3 ; R=Me: 4 ), [Rh(PPh 3 ) 2 (2-Ph 2 PC 6 H 4 NH-κ N ,κ P )] ( 5 ), and [Ir(CO)(PPh 3 )(2-Ph 2 PC 6 H 4 N{C(O)camph-(1 S )}-κ N ,κ P )] ( 6 , C(O)camph-(1 S )=(1 S )-camphanoyl) has been investigated. Out of the complexes tried, only 1 showed significant activity for the reduction of the carbonyl group. Evidence is presented that the catalytic cycle is entered by the formation of the cis- ( H , H ) -cis- ( P , P )-dihydride [IrH 2 (CO)(PPh 3 )(2-Ph 2 PC 6 H 4 NH-κ N ,κ P )] ( 9a ) which can be observed by 1 H NMR under 45 bar H 2 . The homogeneous hydrogenation of five α,β-unsaturated carbonyl compounds (crotonaldehyde, ethyl vinyl ketone, 2-cyclohexen-1-one, benzylideneacetone, and benzylideneacetophenone), in the presence of 1 , proceeded with chemoselectivities for the corresponding allylic alcohols varying between zero for EtC(O)CHCH 2 and 77–78% for PhCHCHC(O)Me and MeCHCHCHO, respectively. Complexes 1 and 5 were fully characterized by X-ray structure analysis.

Facile formation of a heterobimetallic cluster with a cubane-like [Mo3S4Cu]5+ core

Abstract Reaction of the cluster salt [(η 5 -Cp ′ ) 3 Mo 3 S 4 ][pts] ([ 1 ][pts], Cp ′ =methylcyclopentadienyl; pts= p -toluenesulfonate) with CuCl yielded a new heterobimetallic cluster, [(η 5 -Cp ′ ) 3 Mo 3 S 4 Cu(Cl)][pts] ([ 2 ][pts]). X-ray crystal structure determination of [ 1 ][pts] and [ 2 ][pts] showed that the incorporation of CuCl into the Mo 3 S 4 cluster core has only minor consequences on the Mo–Mo and Mo–S distances. The metal atoms in the cluster core of [ 2 ] + form an almost regular tetrahedron. The [ 2 ] + cation conforms to an idealized C 3 v symmetry ignoring the Cp ′ groups since the Cu–Cl bond is almost aligned with the axis defined by the Cu–S(4) cube diagonal.

Solution interaction of O-donor ligand metal complexes with thiocarbonyl compounds—a new general route to metal sulfide materials

Molybdenum and tungsten oxoalkoxides {[MO(OMe)4]; M = Mo, W} and rhenium heptaoxide (Re2O7) reacted at room temperature with thiocarbonyl compounds such as N,N-dimethylthioformamide (DMTF), producing the crystalline metal sulfides MoS2, WS3 and Re2S7, respectively. The reaction mechanism involves, as the first step, the coordination of DMTF to a metal via the sulfur donor atom, followed by the subsequent metathesis of the latter with the doubly bonded oxygen atom. The final product is, depending on reaction conditions, a colloidal metal sulfide or up to 0.1 mm large metal sulfide crystals. By carrying out the reaction within a mesoporous alumina matrix, supported metal sulfide catalysts were obtained in one step. These catalysts were tested for catalytic hydrodesulfurization and their activity compared with catalysts prepared by traditional methods. Reaction of nickel and zinc acetylacetonates and aminoalkoxides with DMTF in hydrocarbon media was found to provide colloids and, on aging, fine powder precipitates of NiS and ZnS.

Ligand vs. Metal Basicity: Reactions of 2-(Diphenylphosphanyl)anilido and 2-(Diphenylphosphanyl)phenolato Complexes of Rhodium(I) and Iridium(I) with HBF4

Treatment of [M(CO)(PPh3)(2-Ph2PC6H4NR-κN,κP)], where M/NR = Rh/NH (1), Rh/NCH3 (2), Ir/NH (3), and Ir/NCH3 (4), with Et2O・HBF4 in CH2Cl2 resulted in protonation at nitrogen with formation of [M(CO)(PPh3)(2-Ph2PC6H4NHR-κN,κP)]BF4 [M/NHR = Rh/NH2 (7), Rh/NHCH3 (8), Ir/NH2 (9), Ir/NHCH3 (10)]. Similar protonation of [Rh(CO)(PPh3)(2-Ph2PC6H4O-κO,κP)] (5) in CH2Cl2 afforded [Rh(CO)(PPh3)(2-Ph2PC6H4OH-κO,κP)]BF4 (11), but furnished [Rh(CO)(PPh3)- (NCCH3)(2-Ph2PC6H4OH-κP)]BF4 (12) if carried out in CH3CN. [Ir(CO)(PPh3)(2-Ph2PC6H4O- κO,κP)] (6) reacted with HBF4 by protonation at the central metal atom and oxidative addition to give [IrH(FBF3)(CO)(PPh3)(2-Ph2PC6H4O-κO,κP)] (13), the substitutionally labile BF4 − ligand of which underwent smooth exchange with neutral donors L producing [IrH(CO)(L)(PPh3)(2- Ph2PC6H4O-κO,κP)]BF4 with L = H2O (14), CH3CN (15) and PPh3 (16). The structures of 6 and 15 were determined by single-crystal X-ray crystallography. Graphical Abstract Ligand vs. Metal Basicity: Reactions of 2-(Diphenylphosphanyl)anilido and 2-(Diphenylphosphanyl)phenolato Complexes of Rhodium(I) and Iridium(I) with HBF4