Group silver complexes

This group showed that isolable silver(I) diaminocarbene complexes can be use in situ instead of free carbenes, to generate the copper carbene complex. The silver salts that precipitates during the formation of the copper complex have not any negative effect on the conversion. This method is advantageous since most of the silver complexes are isolable, air-stable and easily obtained by treatment of the corresponding imidazohnium salt by 0.5 equiv of silver oxide (Scheme 53). The solid structure of 78 was analyzed by X-ray diffraction. 

Attempts to oxidise silver dithiocarbamato complexes with halogens to compounds with the metal in higher oxidation states obviously failed. By addition of iodine to a solution of [Ag(Bu2 fc)]g in CHQ3, an insoluble product is formed with the composition rjA% S> X2dtc) 141). With other alkyl groups similar complexes are obtained. Investigations about the nature of this type of compounds are in progress. 

Several ligands containing pyridine or related groups and sulfur atoms have been synthesized and the silver complexes studied the ligands used are shown in Figure 15. Many of the complexes have a supramolecular structure. 

Silver(I) complexes can also be obtained when the pyridyl N becomes quatemized, if the aliphatic group contains an amine. Thermodynamic data for silver complexes with ligands of the type C5H5N+(CH2) NH (n = 2-5) are given in Table 16.88,89... 

Table 49.357 It was assumed that in all of these cases bonding was primarily through the Group VI donor atom with minimal chelation through the carboxyl groups. This was supported by the apparent absence of a silver complex for X = CH2.

Reaction of the Schiff base ligand A,Ar -bis(o-diphenylphosphinobenzylidene)(ethylene-diamine (49 en=P2) with AgBF4 produced a pale yellow salt. The IR spectrum of this complex showed strong bands due to the imino and BF4 group (v(C=N) 1653 cm-1, v(BFj) 1080 cm-1). The crystal structure of the Cu1 analogue was reported and the copper ion was found to adopt a severely distorted tetrahedral geometry. This strain was manifested in its reactivity since both the copper and silver complex reacted with f-butyl isocyanide. In the case of silver(I) a five-coordinate adduct was obtained, [Ag(en=P2)(Bu NC)]BF4.396... 

Olefins - [FEEDSTOCKS - COALCHEMICALS] (Vol 10) - [FEEDSTOCKS-PETROCHEMICALS] (VollO) - [HYDROCARBONS - SURVEY] (Vol 13) -m automobile exhaust [EXHAUSTCONTROL, AUTOMOTIVE] (Vol 9) -catalyst for stereospeafic polymerization [TITANIUMCOMPOUNDS - INORGANIC] (Vol 24) -esters from [ESTERIFICATION] (Vol 9) -hydroxylation using H202 [HYDROGEN PEROXIDE] (Vol 13) -luminometer ratings [AVIATION AND OTHER GAS TURBINE FUELS] (Vol 3) -osmium oxidations of [PLATINUM-GROUP METALS, COMPOUNDS] (Vol 19) -polymerization [SULFONIC ACIDS] (Vol 23) -reaction with EDA [DIAMINES AND HIGHER AMINES ALIPHATIC] (Vol 8) -silver complexes of [SILVER COMPOUNDS] (Vol 22)... 

Pale and coworkers have demonstrated that silver acetylides may be synthesized with a variety of silver salts in the presence of base in a number of solvents. By treating 1 -hexyne in either deuterated benzene or DMF with silver triflate, the group was able to observe the formation of the Jt-alkyne-silver complex and subsequently the silver acetylide through the use of H, C, and Ag NMR. The incipient Jt-alkyne-silver complex is rapidly deprotonated on addition of diisopropylethylamine, to give the silver acetylide as a white precipitate (Scheme 1.33).89... 

T-7T Stacking or jt-jt interactions are important noncovalent intermolecular interactions, which contribute much to self-assembly when extended structures are formed from building blocks with aromatic moieties. In relation to the rich variety of jt-jt stacking in the crystal structure of silver complexes of phenylenediethynide, related silver complexes of phenylethynide and its homologues with different substituents (-CH3, -QC or the -CH3 group in different positions (0m-, p-) are investigated. 

---