Osmabenzenes from the reactions of HC[triple bond]CCH(OH)C[triple bond]CH with OsX2(PPh3)3 (X = Cl, Br)

Treatment of OsX2(PPh3)3 (X = Cl, Br) with HCCCH(OH)CCH in THF produces OsX2(CH=C(PPh3)CH(OH)CCH)(PPh3)2, which reacts with PPh3 to give osmabenzenes [Os(CHC(PPh3)CHC(PPh3)CH)X2(PPh3)2]+.     

Hydrogenation studies involving halobis(phosphine)-rhodium(I) dimers: use of parahydrogen induced polarisation to detect species present at low concentration

Reaction of [RhCl(PPh3)2]2 with parahydrogen revealed that the binuclear dihydride [Rh(H)2(PPh3)2mu-Cl)2Rh(PPh3)2] and the tetrahydride complex [Rh(H)2(PPh3)2(mu-Cl)]2 are readily formed. While magnetisation transfer from free H2 into both the hydride resonances of the tetrahydride and [Rh(H)2Cl(PPh3)3] is observable, neither transfer into [Rh(H)2(PPh3)2(mu-Cl)2Rh(PPh3)2] nor transfer between the two binuclear complexes is seen. Consequently [Rh(H)2(PPh3)2(mu-Cl)]2 and [Rh(H)2(PPh3)2(mu-Cl)2Rh(PPh3)2] are not connected on the NMR timescale by simple elimination or addition of H2. The rapid exchange of free H2 into the tetrahydride proceeds via reversible halide bridge rupture and the formation of [Rh(H)2(PPh3)2(mu-Cl)RhCl(H)2(PPh3)2]. When these reactions are examined in CD2Cl2, the formation of the solvent complex [Rh(H)2(PPh3)2(mu-Cl)2Rh(CD2Cl2)(PPh3)] and the deactivation products [Rh(Cl)(H)PPh3)2(mu-Cl)(mu-H)Rh(Cl)(H)PPh3)2] and [Rh(Cl)(H)(CD2Cl2)(PPh3)(mu-Cl)(mu-H)Rh(Cl)(H)PPh3)2] is indicated. In the presence of an alkene and parahydrogen, signals corresponding to binuclear complexes of the type [Rh(H)2(PPh3)2(mu-Cl)(2)(Rh)(PPh3)(alkene)] are detected. These complexes undergo intramolecular hydride interchange in a process that is independent of the concentration of styrene and catalyst and involves halide bridge rupture, followed by rotation about the remaining Rh-Cl bridge, and bridge re-establishment. This process is facilitated by electron rich alkenes. Magnetisation transfer from the hydride ligands of these complexes into the alkyl group of the hydrogenation product is also observed. Hydrogenation is proposed to proceed via binuclear complex fragmentation and trapping of the resultant intermediate [RhCl(H)2PPh3)2] by the alkene. Studies on a number of other binuclear dihydride complexes including [(H)(Cl)Rh(PMe3)2(mu-H)(mu-Cl)Rh(CO)(PMe3)], [(H)2Rh(PMe3)2(mu-Cl)2Rh(CO)(PMe3)] and [HRh(PMe3)2(mu-H)(mu-Cl)2Rh(CO)(PMe3)] reveal that such species are able to play a similar role in hydrogenation catalysis. When the analogous iodide complexes [RhIPPh3)2]2 and [RhI(PPh3)3] are examined, [Rh(H)2(PPh3)2(mu-I)2Rh(PPh3)2], [Rh(H)2(PPh3)2(mu-I)]2 and [Rh(H)2I(PPh3)3] are observed in addition to the corresponding binuclear alkene-dihydride products. The higher initial activity of these precursors is offset by the formation of the trirhodium phosphide bridged deactivation product, [[(H)(PPh3)Rh(mu-H)(mu-I)(mu-PPh2)Rh(H)(PPh3)](mu-I)2Rh(H)2PPh3)2]     

Gold and silver complexes with the ferrocenyl phosphine FcCH2PPh2

Linear gold(I) and silver(I) complexes with the ferrocenyl phosphine FcCH2PPh2 [Fc = (eta5-C5H5)Fe(eta5-C5H4)] of the types [AuR(PPh2CH2Fc)], [M(PPh3)(PPh2CH2Fc)]OTf, and [M(PPh2CH2Fc)2]OTf (M = Au, Ag) have been obtained. Three-coordinate gold(I) and silver(I) derivatives of the types [AuCl(PPh2CH2Fc)2] and [M(PPh2CH2Fc)3]X (M = Au, X = ClO4; M = Ag, X = OTf) have been obtained from the corresponding gold and silver precursors in the appropriate molar ratio, although some of them are involved in equilibria in solution. The crystal structures of [AuR(PPh2CH2Fc)] (R = Cl, C6F5), [AuL(PPh2CH2Fc)]OTf (L = PPh3, FcCH2PPh2), [Au(C6F5)3(PPh2CH2Fc)], and [Ag(PPh2CH2Fc)3]OTf have been determined by X-ray diffraction studies.     

有机金催化胺氧化羰化制氨基甲酸酯

自Haruta等报道高分散担载金催化剂对CO有良好的低温水除活性以来,金催化剂的研究开发开始受到关注,各种提载型金催化剂在选择氧化、氮氧化物消除、选择加氢、甲烷完全氧化以及均相有机金配合物催化剂在醇醛缩合、烯烃羰化、锡烷的偶联等反应中均取得了相当好的效果,但与Pt和Pd等贵金属相比,金作为具有潜在多种催化能力的催化材料了解尚少。现在工业上主要使用胺类化合物与剧毒的光气反应制取异氰酸酯,该反应造成设备腐蚀和环境污染,因此用胺类化合物氧化羰化或硝基化合物的还原羰化合成氨基甲酸酯,然后热裂解制取相应的异氰酸酯得到广泛研究,过去主要以含氮配体配位的钯催化剂为代表的贵金属为催化剂催化羰化合成氨基甲酸酯,以有机金配合物作为含氮化合物羰化催化剂的研究则未见报道,本文首次将有机金配合物作为胺类化合物氧化羰化制取氨基甲酸酯的催化剂,取得了与钯催化剂相当的催化效果,反应如下：R（NH2）n CO O2 R^1OH[Au(PPh3)x]yZ／→／PPh3R(NHCO2R^1)n H2O R=Ar-,RCH2-;R^1=CH3-,CH3CH2-;n=1 or 2,x=1 or 2,y=1 or 2;Z=cl,NO3,S。     

An efficient Approach to Modify the Catalyst Activity for the Hydrogenation of Nitrobenzene

Transition metal complexes have been used extensively for the hydrogenation in homogeneous system probably due to their high catalytic selectivities under mild operating conditions. In order to improve the homogeneous catalyst system, some studies on the homogeneous or soluble polymer-supported bimetallic catalysts have been recently carried out and enhanced activity, better selectivity were observed in selective hydrogenation, hydrodehalogenation, carbonylation, hydroformylation and regioselec…     

Coordination and organometallic chemistry of relevance to the rhodium-based catalyst for ethylene hydroamination

The RhCl(3)·3H(2)O/PPh(3)/nBu(4)PI catalytic system for the hydroamination of ethylene by aniline is shown to be thermally stable by a recycle experiment and by a kinetic profile study. The hypothesis of the reduction under catalytic conditions to a Rh(I) species is supported by the observation of a high catalytic activity for complex [RhI(PPh(3))(2)](2). New solution equilibrium studies on [RhX(PPh(3))(2)](2) (X = Cl, I) in the presence of ligands of relevance to the catalytic reaction (PPh(3), C(2)H(4), PhNH(2), X(-), and the model Et(2)NH amine) are reported. Complex [RhCl(PPh(3))(2)](2) shows broadening of the (31)P NMR signal upon addition of PhNH(2), indicating rapid equilibrium with a less thermodynamically stable adduct. The reaction with Et(2)NH gives extensive conversion into cis-RhCl(PPh(3))(2)(NHEt(2)), which is however in equilibrium with the starting material and free Et(2)NH. Excess NHEt(2) yields a H-bonded adduct cis-RhCl(PPh(3))(2)(Et(2)NH)···NHEt(2), in equilibrium with the precursors, as shown by IR spectroscopy. The iodide analogue [RhI(PPh(3))(2)](2) shows less pronounced reactions (no change with PhNH(2), less extensive addition of Et(2)NH with formation of cis-RhI(PPh(3))(2)(NHEt(2)), less extensive reaction of the latter with additional Et(2)NH to yield cis-RhI(PPh(3))(2)(Et(2)NH)···NHEt(2). The two [RhX(PPh(3))(2)](2) compounds do not show any evidence for addition of the corresponding X(-) to yield a putative [RhX(2)(PPh(3))(2)](-) adduct. The product of C(2)H(4) addition to [RhI(PPh(3))(2)](2), trans-RhI(PPh(3))(2)(C(2)H(4)), has been characterized in solution. Treatment of the RhCl(3)·3H(2)O/PPh(3)/nBu(4)PI/PhNH(2) mixture under catalytic conditions yields mostly [RhCl(PPh(3))(2)](2), and no significant halide exchange, demonstrating that the promoting effect of iodide must take place at the level of high energy catalytic intermediates. The equilibria have also been investigated at the computational level by DFT with treatment at the full QM level including solvation effects. The calculations confirm that the bridge splitting reaction is slightly less favorable for the iodido derivative. Overall, the study confirms the active role of rhodium(I) species in ethylene hydroamination catalyzed by RhCl(3)·3H(2)O/PPh(3)/nBu(4)PI and suggest that the catalyst resting state is [RhCl(PPh(3))(2)](2) or its C(2)H(4) adduct, RhCl(PPh(3))(2)(C(2)H(4)), under high ethylene pressure.     

有机金配合物催化的胺羰化制氨基甲酸酯及酰胺

使用一系列有机金配合物HAuCl4、Au(PPH3)Cl、Au(PPh3)2Cl、Au(PPh3)NO3和[Au(PPh3)]2S,催化胺类化合物羰化合氨基甲酸酯和酰胺。其中,Au(PPh3)Cl在合成氨基甲酸酯的反应中催化性能最好,而在合成酰胺的反应中[Au(PPh3)]2S的催化性能最好,两者均优于Pd(PPh32)2Cl2催化剂。     

Synthesis, structure, and reactivity of ruthenium carboxylato and 2-oxocarboxylato complexes bearing the bis(3,5-dimethylpyrazol-1-yl)acetato ligand

A series of ruthenium(II) acetonitrile, pyridine (py), carbonyl, SO2, and nitrosyl complexes [Ru(bdmpza)(O2CR)(L)(PPh3)] (L = NCMe, py, CO, SO2) and [Ru(bdmpza)(O2CR)(L)(PPh3)]BF4 (L = NO) containing the bis(3,5-dimethylpyrazol-1-yl)acetato (bdmpza) ligand, a N,N,O heteroscorpionate ligand, have been prepared. Starting from ruthenium chlorido, carboxylato, or 2-oxocarboxylato complexes, a variety of acetonitrile complexes [Ru(bdmpza)Cl(NCMe)(PPh3)] (4) and [Ru(bdmpza)(O2CR)(NCMe)(PPh3)] (R = Me (5a), R = Ph (5b)), as well as the pyridine complexes [Ru(bdmpza)Cl(PPh3)(py)] (6) and [Ru(bdmpza)(O2CR)(PPh3)(py)] (R = Me (7a), R = Ph (7b), R = (CO)Me (8a), R = (CO)Et (8b), R = (CO)Ph) (8c)), have been synthesized. Treatment of various carboxylato complexes [Ru(bdmpza)(O2CR)(PPh3)2] (R = Me (2a), Ph (2b)) with CO afforded carbonyl complexes [Ru(bdmpza)(O2CR)(CO)(PPh3)] (9a, 9b). In the same way, the corresponding sulfur dioxide complexes [Ru(bdmpza)(O2CMe)(PPh3)(SO2)] (10a) and [Ru(bdmpza)(O2CPh)(PPh3)(SO2)] (10b) were formed in a reaction of the carboxylato complexes with gaseous SO2. None of the 2-oxocarboxylato complexes [Ru(bdmpza)(O2C(CO)R)(PPh3)2] (R = Me (3a), Et (3b), Ph (3c)) showed any reactivity toward CO or SO2, whereas the nitrosyl complex cations [Ru(bdmpza)(O2CMe)(NO)(PPh3)](+) (11) and [Ru(bdmpza)(O2C(CO)Ph)(NO)(PPh3)](+) (12) were formed in a reaction of the acetato 2a or the benzoylformato complex 3c with an excess of nitric oxide. Similar cationic carboxylato nitrosyl complexes [Ru(bdmpza)(O2CR)(NO)(PPh3)]BF4 (R = Me (13a), R = Ph (13b)) and 2-oxocarboxylato nitrosyl complexes [Ru(bdmpza)(O2C(CO)R)(NO)(PPh3)]BF4 (R = Me (14a), R = Et (14b), R = Ph (14c)) are also accessible via a reaction with NO[BF4]. X-ray crystal structures of the chlorido acetonitrile complex [Ru(bdmpza)Cl(NCMe)(PPh3)] (4), the pyridine complexes [Ru(bdmpza)(O2CMe)(PPh3)(py)] (7a) and [Ru(bdmpza)(O2CC(O)Et)(PPh3)(py)] (8b), the carbonyl complex [Ru(bdmpza)(O2CPh)(CO)(PPh3)] (9b), the sulfur dioxide complex [Ru(bdmpza)(O2CPh)(PPh3)(SO2)] (10b), as well as the nitrosyl complex [Ru(bdmpza)(O2C(CO)Me)(NO)(PPh3)]BF4 (14a), are reported. The molecular structure of the sulfur dioxide complex [Ru(bdmpza)(O2CPh)(PPh3)(SO2)] (10b) revealed a rather unusual intramolecular SO2-O2CPh Lewis acid-base adduct.     

Iridium(III) complexes formed by O-H and/Or C-H activation of 2-(arylazo)phenols

Reaction of 2-(arylazo)phenols with [Ir(PPh(3))(3)Cl] in refluxing ethanol in the presence of a base (NEt(3)) affords complexes of three different types, viz. [Ir(PPh(3))(2)(NO-R)(H)Cl] (R = OCH(3), CH(3), H, Cl and NO(2)), [Ir(PPh(3))(2)(NO-R)(H)(2)] and [Ir(PPh(3))(2)(CNO-R)(H)]. Structures of the [Ir(PPh(3))(2)(NO-Cl)(H)Cl], [Ir(PPh(3))(2)(NO-Cl)(H)(2)] and [Ir(PPh(3))(2)(CNO-Cl)(H)] complexes have been determined by X-ray crystallography. In the [Ir(PPh(3))(2)(NO-R)(H)Cl] and [Ir(PPh(3))(2)(NO-R)(H)(2)] complexes, the 2-(arylazo)phenolate ligands are coordinated to the metal center as monoanionic bidentate N,O-donors, whereas in the [Ir(PPh(3))(2)(CNO-R)(H)] complexes, they are coordinated to iridium as dianionic tridentate C,N,O-donors. In all three products formed in ethanol, the two PPh(3) ligands are trans. Reaction of 2-(arylazo)phenols with [Ir(PPh(3))(3)Cl] in refluxing toluene in the presence of NEt(3) affords complexes of two types, viz. [Ir(PPh(3))(2)(CNO-R)(H)] and [Ir(PPh(3))(2)(CNO-R)Cl]. Structure of the [Ir(PPh(3))(2)(CNO-Cl)Cl] complex has been determined by X-ray crystallography, and the 2-(arylazo)phenolate ligand is coordinated to the metal center as a dianionic tridentate C,N,O-donor and the two PPh(3) ligands are cis. All of the iridium(III) complexes show intense MLCT transitions in the visible region. Cyclic voltammetry shows an Ir(III)-Ir(IV) oxidation on the positive side of SCE and an Ir(III)-Ir(II) reduction on the negative side for all of the products.     

Interpolymetallic assembly of d8-d10 sulfide aggregates from [Pt2(PPh3)4(mu-S)2] and group 12 metals

A series of heterometallic Pt-M (M=Zn and Cd) sulfide aggregates with growing nuclearities (Pt2M), (Pt4M), and (Pt4M2), viz., [ZnPt2Cl2(PPh3)4(mu3-S)2] (2), [CdPt2Cl2(PPh3)4(mu3-S)2] (3), [Pt2(PPh3)4(mu3-S)2]2[ZnSO4]2 (4), [Pt2(PPh3)4(mu3-S)2]2[CdSO4]2.H2O (5), [CdPt4(PPh3)8(mu3-S)4][ClO4]2 (7), and [ZnPt4(PPh3)8(mu3-S)4][ClO4]2 (8), have been prepared from Pt2(PPh3)4(mu-S)2 (1) with appropriate zinc and cadmium substrates. The structures have been determined by single-crystal X-ray diffraction. The supporting anions play an active role in the structural assembly process. An unexpected disintegration complex [Pt2(S2CH2)Cl(PPh3)4][PF6] (6) has also been isolated and characterized by single-crystal X-ray diffraction. The mechanism of the formation of 6 is proposed.     

Penta- and hexaruthenium carbonyl 'raft' complexes supported by monocarborane cage ligands

Reaction between [PPh4][closo-4-CB8H9] and [Ru3(CO)12] in refluxing toluene affords the unprecedented hexaruthenium metallacarborane salt [PPh4][2,3,7-{Ru(CO)3}-2,6,11-{Ru(CO)3}-7,11,12-{Ru(CO)3}-3,6,12-(micro-H)3-2,2,7,7,11,11-(CO)6-closo-2,7,11,1-Ru3CB8H6] (1a), which contains a planar Ru6 'raft' supported by a {CB8} monocarborane cluster. Addition of [CuCl(PPh3)]4 and Tl[PF6] to a CH2Cl2 solution of 1a results in simple cation replacement, forming the analogous [Cu(PPh3)3]+ salt (1b). The phenyl-substituted monocarborane [NEt4][6-Ph-nido-6-CB9H11] reacts with [Ru3(CO)12] in refluxing 1,2-dimethoxyethane to afford the pentaruthenium cluster species [N(PPh3)2][2,3,7-{Ru(CO)3}-3,4,8-{Ru(CO)3}-7,8-(micro-H)2-1-Ph-2,2,3,3,4,4-(CO)6-hypercloso-2,3,4,1-Ru3CB8H6] (2), after addition of [N(PPh3)2]Cl. Treatment of 2 with [CuCl(PPh3)]4 and Tl[PF6] in CH2Cl2 forms the zwitterionic complex [10,12-{exo-Cu(PPh3)2}-2,3,7-{Ru(CO)3}-3,4,8-{Ru(CO)3}-7,8,10,12-(micro-H)4-1-Ph-2,2,3,3,4,4-(CO)6-hypercloso-2,3,4,1-Ru3CB8H4] (3). Substitution of CO by PPh3 with concomitant cation replacement occurs on introduction of [AuCl(PPh3)], Tl[PF6], and PPh3 to a CH2Cl2 solution of 2, forming [Au(PPh3)2][2,3,7-{Ru(CO)2PPh3}-3,4,8-{Ru(CO)2PPh3}-7,8-(micro-H)2-1-Ph-2,2,3,3,4,4-(CO)6-hypercloso-2,3,4,1-Ru3CB8H6] (4). Crystallographic studies confirmed the cluster architectures in 1b, 2, and 3.     

Synthesis, structure, and reactivity of palladacycles that contain a chiral rhenium fragment in the backbone: New cyclometalation and catalyst design strategies

The bromocyclopentadienyl complex [(eta5-C5H4Br)Re(CO)3] is converted to racemic [(eta5-C5H4Br)Re(NO)(PPh3)(CH2PPh2)] (1 b) similarly to a published sequence for cyclopentadienyl analogues. Treatment of enantiopure (S)-[(eta5-C5H5)Re(NO)(PPh3)(CH3)] with nBuLi and I2 gives (S)-[(eta5-C5H4I)Re(NO)(PPh3)(CH3)] ((S)-6 c; 84 %), which is converted (Ph3C+ PF6 -, PPh2H, tBuOK) to (S)-[(eta5-C5H4I)Re(NO)(PPh3)(CH2PPh2)] ((S)-1 c). Reactions of 1 b and (S)-1 c with Pd[P(tBu)3]2 yield [{(eta5-C5H4)Re(NO)(PPh3)(mu-CH2PPh2)Pd(mu-X)}2] (10; X = b, Br, rac/meso, 88 %; c, I, S,S, 22 %). Addition of PPh3 to 10 b gives [(eta5-C5H4)Re(NO)(PPh3)(mu-CH2PPh2)Pd(PPh3)(Br)] (11 b; 92 %). Reaction of (S)-[(eta5-C5H5)Re(NO)(PPh3)(CH2PPh2)] ((S)-2) and Pd(OAc)(2) (1.5 equiv; toluene, RT) affords the novel Pd3(OAc)4-based palladacycle (S,S)-[(eta5-C5H4)Re(NO)(PPh3)(mu-CH2PPh2)Pd(mu-OAc)2Pd(mu-OAc)2Pd(mu-PPh2CH2)(Ph3P)(ON)Re(eta5-C5H4)] ((S,S)-13; 71-90 %). Addition of LiCl and LiBr yields (S,S)-10 a,b (73 %), and Na(acac-F6) gives (S)-[(eta5-C5H4)Re(NO)(PPh3)(mu-CH2PPh2)Pd(acac-F6)] ((S)-16, 72 %). Reaction of (S,S)-10 b and pyridine affords (S)-[(eta5-C5H4)Re(NO)(PPh3)(mu-CH2PPh2)Pd(NC5H5)(Br)] ((S)-17 b, 72 %); other Lewis bases yield similar adducts. Reaction of (S)-2 and Pd(OAc)2 (0.5 equiv; benzene, 80 degrees C) gives the spiropalladacycle trans-(S,S)-[{(eta5-C5H4)Re(NO)(PPh3)(mu-CH2PPh2)}2Pd] (39 %). The crystal structures of (S)-6 c, 11 b, (S,S)- and (R,R)-132 C7H8, (S,S)-10 b, and (S)-17 b aid the preceding assignments. Both 10 b (racemic or S,S) and (S)-16 are excellent catalyst precursors for Suzuki and Heck couplings.     

New highly stable metallabenzenes via nucleophilic aromatic substitution reaction

Treatment of the ruthenabenzene [Ru{CHC(PPh(3))CHC(PPh(3))CH}Cl(2)(PPh(3))(2)]Cl (1) with excess 8-hydroxyquinoline in the presence of CH(3)COONa under air atmosphere produced the S(N)Ar product [(C(9) H(6)NO)Ru{CHC(PPh(3))CHC(PPh(3))C}(C(9)H(6)NO)(PPh(3))]Cl(2) (3). Ruthenabenzene 3 could be stable in the solution of weak alkali or weak acid. However, reaction of 3 with NaOH afforded a 7:1 mixture of ruthenabenzenes [(C(9)H(6)NO)Ru{CHC(PPh(3))CHCHC}(C(9)H(6)NO)(PPh(3))]Cl (4) and [(C(9)H(6)NO)Ru{CHCHCHC(PPh(3))C}(C(9)H(6)NO)(PPh(3))]Cl (5), presumably involving a P-C bond cleavage of the metallacycle. Complex 3 was also reactive to HCl, which results in a transformation of 3 to ruthenabenzene [Ru{CHC(PPh(3))CHC(PPh(3))C}Cl(2)(C(9)H(6)NO)(PPh(3))]Cl (6) in high yield. Thermal stability tests showed that ruthenabenzenes 4, 5, and 6 have remarkable thermal stability both in solid state and in solution under air atmosphere. Ruthenabenzenes 4 and 5 were found to be fluorescent in common solvents and have spectral behaviors comparable to those organic multicyclic compounds containing large π-extended systems.     

Sigma-organyl complexes of ruthenium and osmium supported by a mixed-donor ligand

A series of vinyl, aryl, acetylide and silyl complexes [Ru(R)(kappa2-MI)(CO)(PPh3)2] (R = CH=CH2, CH=CHPh, CH=CHC6H4CH3-4, CH=CH(t)Bu, CH=2OH, C(C triple bond CPh)=CHPh, C6H5, C triple bond CPh, SiMe2OEt; MI = 1-methylimidazole-2-thiolate) were prepared from either [Ru(R)Cl(CO)(PPh3)2] or [Ru(R)Cl(CO)(BTD)(PPh3)2](BTD = 2,1,3-benzothiadiazole) by reaction with the nitrogen-sulfur mixed-donor ligand, 1-methyl-2-mercaptoimidazole (HMI), in the presence of base. In the same manner, [Os(CH=CHPh)(kappa2-MI)(CO)(PPh3)2] was prepared from [Os(CH=CHPh)(CO)Cl(BTD)(PPh3)2]. The in situ hydroruthenation of 1-ethynylcyclohexan-1-ol by [RuH(CO)Cl(BTD)(PPh3)2] and subsequent addition of the HMI ligand and excess sodium methoxide yielded the dehydrated 1,3-dienyl complex [Ru(CH=CHC6H9)(kappa2-MI)(CO)(PPh3)2]. Dehydration of the complex [Ru(CH=CHCPh2OH)(kappa2-MI)(CO)(PPh3)2] with HBF4 yielded the vinyl carbene [Ru(=CHCH=CPh2)(kappa2-MI)(CO)(PPh3)2]BF4. The hydride complexes [MH(kappa2-MI)(CO)(PPh3)2](M = Ru, Os) were obtained from the reaction of HMI and KOH with [RuHCl(CO)(PPh3)3] and [OsHCl(CO)(BTD)(PPh3)2], respectively. Reaction of [Ru(CH=CHC6H4CH3-4)(kappa2-MI)(CO)(PPh3)2] with excess HC triple bond CPh leads to isolation of the acetylide complex [Ru(C triple bond CPh)(kappa2-MI)(CO)(PPh3)2], which is also accessible by direct reaction of [Ru(C triple bond CPh)Cl(CO)(BTD)(PPh3)2] with 1-methyl-2-mercaptoimidazole and NaOMe. The thiocarbonyl complex [Ru(CPh = CHPh)Cl(CS)(PPh3)2] reacted with HMI and NaOMe without migration to yield [Ru(CPh= CHPh)(kappa2-MI)(CS)(PPh3)2], while treatment of [Ru(CH=CHPh)Cl(CO)2(PPh3)2] with HMI yielded the monodentate acyl product [Ru{eta(1)-C(=O)CH=CHPh}(kappa2-MI)(CO)(PPh3)2]. The single-crystal X-ray structures of five complexes bearing vinyl, aryl, acetylide and dienyl functionality are reported.     

Syntheses and molecular structure of some Rh and Ru complexes with the chelating diphenyl (2-pyridyl)phosphine ligand

The rhodium(III) complex mer,cis-[RhCl3(PPh2py-P,N)(PPh2py-P)] (1) (PPh2py = diphenyl (2-pyridyl)phosphine) has been prepared from RhCl3 x 3H2O and PPh2py and converted to the trans,cis-[RhCl2(PPh2py-P,N)2]PF6 (2) in acetone solution by treatment with Ag+ and PF6(-). Ruthenium(III) and ruthenium(II) compounds with PPh2py, mer,cis-[RuCl3(PPh2py-P,N)(PPh2py-P)] (3) and mer-[RuCl(PPh2py-P,N)2(PPh2py-P)]Cl (5) have been obtained from DMSO precursor complexes. In a chloroform solution, complex (5) isomerizes to fac-[RuCl(PPh2py-P,N)2(PPh2py-P)]Cl (fac-5). All compounds have been characterized by MS, UV-vis, IR, and 1H and 31P{1H} NMR spectroscopy, and the Ru(III) compound has been characterized by EPR spectroscopy as well. The crystal structures of 1, 2, 3, and fac-5 have been determined. In all compounds under investigation, at least one pyridylphosphine acts as a chelate ligand. The 31P chemical shifts for chelating PPh2py-P,N depend on the Ru-P bond lengths.     

One-step synthesis of alkenyl ketone complexes from Cp*RhCl2(PPh3), alkyne and H2O in the presence of KPF6

The reaction of Cp*RhCl2(PPh3) 1 with 1-alkyne and H2O in the presence of KPF6 afforded the alkenyl ketone complex [Cp*Rh(PPh3)(CPh=CHCOCH2R)](PF6) [R = p-tolyl (3a), R = Ph (3b)], whereas Cp*IrCl2(PPh3) 2 or [(eta 6-C6Me6)RuCl2(PPh3) gave the corresponding [Cp*IrCl(CO)(PPh3)](PF6) 5a and [(eta 6-C6Me6)RuCl(CO)(PPh3)](PF6).     

Yttrium and lanthanide complexes having a chiral phosphanylamide in the coordination sphere

The chiral phosphanylamides {N(R-CHMePh)(PPh(2))}(-) and {N(S-CHMePh)(PPh(2))}(-) were introduced into rare earth chemistry. Transmetalation of the enantiomeric pure lithium compounds Li{N(R-CHMePh)(PPh(2))} (1a) and Li{N(S-CHMePh)(PPh(2))} (1b) with lanthanide bis(phosphinimino)methanide dichloride [{CH(PPh(2)NSiMe(3))(2)}LnCl(2)](2) in a 2:1 molar ratio in THF afforded the enantiomeric pure complexes [{CH(PPh(2)NSiMe(3))(2)}Ln(Cl){eta(2)-N(R-CHMePh)(PPh(2))}] (Ln = Er (2a), Yb (3a), Lu (4a)) and [{CH(PPh(2)NSiMe(3))(2)}Ln(Cl){eta(2)-N(S-CHMePh)(PPh(2))}] (Ln = Er (2b), Yb (3b), Lu (4b)). The solid-state structures of 2a and 3a,b were established by single-crystal X-ray diffraction. Attempts to synthesize compounds 3 in a one-pot reaction starting from K{CH(PPh(2)NSiMe(3))(2)}, YbCl(3), and 1 resulted in the lithium chloride incorporated complex [{(Me(3)SiNPPh(2))(2)CH}Yb(mu-Cl)(2)LiCl(THF)(2)] (5). In an alternative approach to give chiral rare earth compounds in a one-pot reaction 1a or 1b was reacted with LnCl(3) and K(2)C(8)H(8) to give the enantiomeric pure cyclooctatetraene compounds [{eta(2)-N(R-CHMePh)(PPh(2))}Ln(eta(8)-C(8)H(8))] (Ln = Y (6a), Er (7a), Yb (8)) and [{eta(2)-N(S-CHMePh)(PPh(2))}Ln(eta(8)-C(8)H(8))] (Ln = Y (6b), Er (7b)). The structures of 6a,b, 7a, and 8 were confirmed by single-crystal X-ray diffraction in the solid state.     

Syntheses, structural determinations of [Ru(ROCS2)2(PPh3)2](+/0) pairs, and kinetic analyses of thermal reactions involving transient trans-[Ru(iPrOCS2)2(PPh3)2] species (ROCS2(-) = ethyl- or isopropyldithiocarbonate and PPh3 = triphenylphosphine)

Controlled-potential electrochemical oxidation of cis-[Ru(ROCS2)2(PPh3)2] (R = Et, iPr) yielded corresponding Ru(III) complexes, and the crystal structures of cis-[Ru(ROCS2)2(PPh3)2] and trans-[Ru(ROCS2)2(PPh3)2](PF6) were determined. Both pairs of complexes exhibited almost identical coordination structures. The Ru-P distances in trans-[Ru(III)(ROCS2)2(PPh3)2](PF6) [2.436(3)-2.443(3) A] were significantly longer than those in cis-[Ru(II)(ROCS2)2(PPh3)2] [2.306(1)-2.315(2) A]: the smaller ionic radius of Ru(III) than that of Ru(II) stabilizes the trans conformation for the Ru(III) complex due to the steric requirement of bulky phosphine ligands while mutual trans influence by the phosphine ligands induces significant elongation of the Ru(III)-P bonds. Cyclic voltammograms of the cis-[Ru(ROCS2)2(PPh3)2] and trans-[Ru(ROCS2)2(PPh3)2]+ complexes in dichloromethane solution exhibited typical dual redox signals corresponding to the cis-[Ru(ROCS2)2(PPh3)2](+/0) (ca. +0.15 and +0.10 V vs ferrocenium/ferrocene couple for R = Et and iPr, respectively) and to trans-[Ru(ROCS2)2(PPh3)2](+/0) (-0.05 and -0.15 V vs ferrocenium/ferrocene for R = Et and iPr, respectively) couples. Analyses on the basis of the Nicholson and Shain's method revealed that the thermal disappearance rate of transient trans-[Ru(ROCS2)2(PPh3)2] was dependent on the concentration of PPh3 in the bulk: the rate constant for the intramolecular isomerization reaction of trans-[Ru(iPrOCS2)2(PPh3)2] was determined as 0.338 +/- 0.004 s(-1) at 298.3 K (deltaH* = 41.8 +/- 1.5 kJ mol(-1) and deltaS* = -114 +/- 7 J mol(-1) K(-1)), while the dissociation rate constant of coordinated PPh3 from the trans-[Ru(iPrOCS2)2(PPh3)2] species was estimated as 0.113 +/- 0.008 s(-1) at 298.3 K (deltaH* = 97.6 +/- 0.8 kJ mol(-1) and deltaS* = 64 +/- 3 J mol(-1) K(-1)), by monitoring the EC reaction (electrode reaction followed by chemical processes) at different concentrations of PPh3 in the bulk. It was found that the trans to cis isomerization reaction takes place via the partial dissociation of iPrOCS2(-) from Ru(II), contrary to the previous claim that it takes place by the twist mechanism.     

Rhenium(V) and technetium(V) complexes with phosphoraneimine and phosphoraneiminato ligands

Air-stable rhenium(V) nitrido complexes are formed when [ReOCl3(PPh3)2], [NBu4][ReOCl4], or [NBu4][ReNCl4] are treated with an excess of silylated phosphoraneiminates of the composition Me3SiNPPh3 or Ph2P(NSiMe3)CH2PPh2 in CH2Cl2. Complexes of the compositions [ReNCl(Ph2PCH2PPh2NH)2]Cl (1), [ReN(OSiMe3)(Ph2PCH2PPh2NH)2]Cl (2) or [ReNCl2(PPh3)2] (3) were isolated and structurally characterized. The latter compound was also produced during a reaction of the rhenium(III) precursor [ReCl3(PPh3)2(CH3CN)] and Me3SiNPPh3. Nitrogen transfer from the phosphorus to the rhenium atoms and the formation of nitrido ligands were observed in all examples. All products of reactions with an excess of the potentially chelating phosphoraneiminate Me3SiNP(Ph2)CH2PPh2 contain neutral Ph2PCH2PPh2NH ligands. The required protons are supplied by a metal-induced decomposition of the solvent dichloromethane. The Re-N(imine) bond lengths (2.055-2.110 A) indicate single bonds, whereas the N-P bond with lengths between 1.596 A and 1.611 A reflect considerable double bond character. An oxorhenium(V) phosphoraneiminato complex, the dimeric compound [ReOCl2(mu-N-Ph2PCH2PPh2N)]2 (4), is formed during the reaction of [NBu4][ReOCl4] with an equivalent amount of Ph2P(NSiMe3)CH2PPh in dry acetonitrile. The blue neutral complex with two bridging phosphoraneiminato units is stable as a solid and in dry solvents. It decomposes in solution, when traces of water are present. The rhenium-nitrogen distances of 2.028(3) and 2.082(3) A are in the typical range of bridging phosphoraneiminates and an almost symmetric bonding mode. Technetium complexes with phosphoraneimine ligands were isolated from reactions of [NBu4][TcOCl4] with Me3SiNPPh3, and [NBu4][TcNCl4] with Me3SiNP(Ph2)CH2PPh2. Nitrogen transfer and the formation of a five-coordinate nitrido species, [TcNCl2(HNPPh3)2] (5), was observed in the case of the oxo precursor, whereas reduction of the technetium(VI) starting material and the formation of the neutral technetium(V) complex [TcNCl2(Ph2PCH2PPh2NH)] (6) or [TcNCl(Ph2PCH2PPh2NH)2]Cl (7) was observed in the latter case. Both technetium complexes are air stable and X-ray structure determinations show bonding modes of the phosphoraneimines similar to those in the rhenium complexes.     

Reactivity of a tin(II) (iminophosphinoyl)(thiophosphinoyl)methanediide complex toward sulfur: synthesis and 119Sn Mössbauer spectroscopic studies of [{(μ-S)SnC(PPh2═NSiMe3)(PPh2═S)}3Sn(μ3-S)

Reaction of [(PPh(2)═NSiMe(3))(PPh(2)═S)CSn:](2) (1) with elemental sulfur in toluene afforded [{(μ-S)Sn(IV)C(PPh(2)═NSiMe(3))(PPh(2)═S)}(3)Sn(II)(μ(3)-S)] (2) and [CH(2)(PPh(2)═NSiMe(3))(PPh(2)═S)] (3). Compound 2 comprises a Sn(II)S moiety coordinated with the Sn(IV) and S atoms of a trimeric 2-stannathiomethendiide {(PPh(2)═NSiMe(3))(PPh(2)═S)CSn(μ-S)}(3). Compound 2 has been characterized by NMR spectroscopy, (119)Sn M?ssbauer studies, X-ray crystallography, and theoretical studies. (119)Sn NMR spectroscopy and M?ssbauer studies show the presence of Sn(IV) and Sn(II) atoms in 2. X-ray crystallography suggests that the Sn(II)S moiety does not have multiple bond character. Theoretical studies illustrate that the C(methanediide)-Sn bonds comprise a lone pair orbital on each C(methanediide) atom and an C-Sn occupied σ orbital.