196,107 research outputs found
Preparation of methylhydrazine and methyldiazene complexes of molybdenum and tungsten
No full textNitrosyl complexes [M(CO) 3(NO)L 2]BPh 4 (2, 5) [M = Mo, W; L = PPh(OEt) 2, PPh 2OEt] were prepared by allowing carbonyl compounds M(CO) 4L 2 (1, 4) to react with NOPF 6 in CH 2Cl 2. Dicarbonyl complex [W(CO) 2(NO){PPh(OEt) 2} 3]BPh 4 (7) was also prepared by reacting W(CO) 3[PPh(OEt) 2] 3 (6) with NOPF 6. Treatment of nitrosyl complexes 2, 5 with [NEt 4]Br gave bromide derivative [MBr(CO) 2(NO)L 2]BPh 4 (3). Hydrazine complexes [M(CO)(RNHNH 2)(NO)L 3]BPh 4 (8, 9, 10) (R = H, CH 3) were prepared by allowing nitrosyl complexes 2, 5 to react with hydrazine RNHNH 2 in CH 2Cl 2. Reaction of methylhydrazine complexes [M(CO)(CH 3NHNH 2)(NO)L 3]BPh 4 (8, 10) with Pb(OAc) 4 at -30°C resulted in selective oxidation of hydrazine, affording the corresponding methyldiazene derivatives [M(CO)(CH 3NNH)(NO)L 3]BPh 4 (11, 12). The complexes were characterised spectroscopically (IR and NMR), and a geometry in solution was also established. © 2012 Elsevier Ltd. All rights reserved
Synthesis and Reactivity of Germyl Complexes of Manganese and Rhenium
No full textTrichlorogermyl complexes M(GeCl3)(CO)nP 5- n (1-4) [M = Mn, Re; n = 2, 3; P = PPh(OEt)2 (a), P(OEt)3 (b)] were prepared by allowing chloro compounds MCl(CO) nP5- n to react with an excess of GeCl2• dioxane in 1,2-dichloroethane. Treatment of compounds 1-4 with LiAlH4 in thf yielded trihydridegermyl derivatives M(GeH3)(CO) nP5-n (5-8), whereas treatment of the same complexes with NaBH4 in ethanol afforded triethoxygermyl derivatives M[Ge(OEt) 3](CO)nP5-n (9-11). Trimethylgermyl compounds M(GeMe3)(CO)nP5-n (12, 13) and the alkynylgermyl derivative Mn[Ge(CCPh)3](CO)3[PPh(OEt) 2]2 (14a) were also prepared by allowing trichlorogermyl compounds 1-4 to react with either MgBrMe or Li+CCPh-, respectively, in thf. Treatment of compound Re(GeCl3)(CO) 3[PPh(OEt)2]2 (4a) with SnCl 2•2H2O gave the stannyl-germyl derivative Re[GeCl2(SnCl3)](CO)3[PPh(OEt) 2]2 (15a). The complexes were characterised by spectroscopy and X-ray crystal structure determination of 4a, 5a, and 13a. © 2011 Elsevier B.V. All rights reserved
Preparation and reactivity of dihydrogen complexes [MX(eta2-H2)P4]BF4 (M = Ru or Os; X = halogenide or SEt-; P = phosphite)
No full textPreparation and Reactivity of Hydrazine Complexes of Rhenium: Synthesis of 1,2-Diazene NH=NH and Methyleneimine CH2=NH Derivatives
No full textDiazo complexes of osmium: preparation of binuclear derivatives with bis(aryldiazene) and bis(aryldiazenido) bridging ligands
No full textA Replication Framework for Program-to-Program Interaction across Unreliable Networks and its Implementation in a Servlet Container
No full textWe propose a service replication framework for unreliable networks. The service exhibits the same consistency guarantees about the order of execution of operation requests as its non-replicated implementation. Such guarantees are preserved in spite of server replica failure, network failure (either between server replicas or between a client and a server replica) and irrespective of when the failure occurs. Moreover, the service guarantees that in case a client sends an “update” request multiple times, there is no risk that the request be executed multiple times. No hypothesis about the timing retransmission policy of clients are made, e.g., the very same request might even arrive at different server replicas simultaneously. All these features make the proposed framework particularly suitable for interaction between remote programs, a scenario that is gaining increasing importance. We discuss a prototype implementation of our replication framework based on Tomcat, a very popular Java-based web server. The prototype comes into two flavors: replication of HTTP client session data and replication of a counter accessed as a web service
New Mononitrosyl Derivatives of Iron, Ruthenium and Osmium
No full textHydride nitrosyl complexes [MH(NO)L4][PF6]2 1 [M = Ru or Os; L = P(OEt)2Ph] were prepared by allowing [MH(η2-H2)L4]BF4 to react with NO+PF6- at -80 °C in CH2Cl2. Five-co-ordinate [Fe(NO)L4]PF6 2 was obtained from the same reaction in the case of iron. Deprotonation of cations [MH(NO)L4]2+ 1 with NEt3 or OH- led to the formation of new mononitrosyl cations [M(NO)L4]+ 2 (M = Ru or Os). All 2 react with HBF4·Et2O to give [MH(NO)L4]2+ derivatives, according to the equilibrium [MH(NO)L4]2+ ⇄ [M(NO)L4]+. Characterization of nitrosyls 1 and 2 by infrared, 1H and 31P NMR spectra is reported. The reaction of [M(NO)L4]+ 2 (M = Fe, Ru or Os) with isocyanides and CO was examined and led to the synthesis of [M(NO)(CNR)2L2]+ (M = Fe), [M(CNR)4L2]2+ (M = Ru or Os), and [M(NO)(CO)2L2]+ (M = Fe or Ru) derivatives (R = 4-MeC6H4 or 4-MeOC6H4). The [M(NO)L4]PF6 complexes are also oxidized by bromine to produce [RuBr2(NO)L3]+ and [OsBr(NO)L4]2+. © Copyright 1992 by the Royal Society of Chemistry
Preparation and Reactivity of Half-sandwich Hydrazine Complexes of Ruthenium and Osmium
No full textHydrazine complexes [MCl(η6-p-cymene)(RNHNH 2)L]BPh4 (1-6) [M = Ru, Os; R = H, Me, Ph; L = P(OEt) 3, PPh(OEt)2, PPh2OEt] were prepared by allowing dichloro complexes MCl2(η6-p-cymene)L to react with hydrazines RNHNH2 in the presence of NaBPh4. Treatment of ruthenium complexes [RuCl(η6-p-cymene)(RNHNH 2)L]BPh4 with Pb(OAc)4 led to acetate complex [Ru(κ2-O2CCH3)(η6-p- cymene)L]BPh4 (7). Instead, the reaction of osmium derivatives [OsCl(η6-p-cymene)(CH3NHNH2)L]BPh 4 with Pb(OAc)4 afforded the methyldiazenido complex [Os(CH3N2)(η6-p-cymene)L}]BPh4 (8). Treatment with HCl of this diazenido complex 8 led to the methyldiazene cation [OsCl(CH3NNH)(η6-p-cymene)L}]+ (9+). The complexes were characterised spectroscopically and by X-ray crystal structure determination of [OsCl(η6-p-cymene) (PhNHNH2){PPh(OEt)2}]BPh4 (6b) and [Ru(κ2-O2CCH3)(η6-p- cymene){PPh(OEt)2}]BPh4 (7b). © 2011 Elsevier B.V. All rights reserved
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