Silver complex compounds

Simple ABO compounds in addition to BaTiO are cadmium titanate [12014-14-17, CdTiO lead titanate [12060-00-3] PbTiO potassium niobate [12030-85-2] KNbO sodium niobate [12034-09-2], NaNbO silver niobate [12309-96-5], AgNbO potassium iodate [7758-05-6], KIO bismuth ferrate [12010-42-3], BiFeO sodium tantalate, NaTaO and lead zirconate [12060-01 -4], PbZrO. The perovskite stmcture is also tolerant of a very wide range of multiple cation substitution on both A and B sites. Thus many more complex compounds have been found (16,17), eg, (K 2 i/2) 3 ... 

Silver and sulfur combine even in the cold to form silver sulfide. The tendency of silver to tarnish is an example of the ease with which silver and sulfur compounds react. PoHshes that contain silver complexing agents, such as chloride ion or thiourea, are used to remove silver tarnish. 

Sulfur Complexes. Silver compounds other than sulfide dissolve in excess thiosulfate. Stable silver complexes are also formed with thiourea. Except for the cyanide complexes, these sulfur complexes of silver are the most stable. In photography, solutions of sodium or ammonium thiosulfate fixers are used to solubilize silver hahdes present in processed photographic emulsions. When insoluble silver thiosulfate is dissolved in excess thiosulfate, various silver complexes form. At low thiosulfate concentrations, the principal silver species is Ag2(S203) 2j high thiosulfate concentrations, species such as Ag2(S203) 3 are present. Silver sulfide dissolves in alkaline sulfide solutions to form complex ions such as Ag(S 2 Ag(HS) 4. These ions are... 

Silver(II) Compounds. Sdver(II) is stabilized by coordination with nitrogen heterocychc bases, such as pyridine and dipyridyl. These cationic complexes are prepared by the peroxysulfate oxidation of silver(I) solutions in the presence of an excess of the ligand. An extensive review of the higher oxidation states of silver has beenpubhshed (21). 

Silver(III) Compounds. No simple silver(Ill) compounds exist. When mixtures of potassium or cesium haUdes are heated with silver hahdes ia a stream of fluorine gas, yellow KAgF [23739-18-6] or CsAgF [53585-89-0] respectively, are obtained. These compounds are diamagnetic and extremely sensitive to moisture (21). When Ag2S04 is treated with aqueous potassium persulfate ia the presence of ethylenedibiguanidinium sulfate, the relatively stable Ag(Ill)-ethylenebiguanide complex is formed. 

Release by Silver-Assisted Cleavag e. A soluble silver complex formed imagewise in the undeveloped areas of the silver haUde layer may be used to effect a cleavage reaction that releases a dye or a dye precursor. The process yields positive dye transfer images directiy with negative-working emulsions (46). An example is the silver-assisted cleavage of a dye-substituted thiazolidine compound, as shown in equation 7. 

Ti in [Ti(> 2-Cl04)4] and Ni" in [Ni(>j -C104)L2] where L is a chiral bidenlate organic ligand.Sometimes both and modes occur in the same compound. The biden-latc bridging mode occurs in the silver complex [Ag /x,>j -00(0)20- (m-xylene)2]- The structure of appropriate segments of some of these compounds arc in Fig. 17.23. The distinction between coordinated and non-coordinaied ( ionic ) perchlorate is sometimes hard to make and there is an almost continuous... 

Oxidation of the complexes [Ag(Py)4][MoF6] and [Ag(Py)2][UF6] in acetonitrile by MoF6 and UF6, respectively, leads to the silver(III) compounds [Ag(Py)4(NCMe)][MoF6]3 and [Ag(Py)2(NC-Me)3][UF6]3, which are strong oxidizing agents.167 Other pyridine silver(III) complexes have been obtained by oxidation of silver nitrate and ammonia with ammonium peroxydisulfate in aqueous... 

The reaction of A-benzyl-C-imidazolyllithium with [Ag(N03)(SMe)2] affords the corresponding C-imidazolylsilver (Equation (3)), which has been proposed by molecular weight determination to be trimeric.297 A-Functionalized C-imidazolylsilver compounds or carbene-type silver complexes are obtained by reaction of the imidazolium salt with Ag20 or Ag2C03 some of these are shown in Figure 4 298,299... 

Other polydentate ligands are polyamines and related ligands. Stability constants of silver(I) complexes with polyamines in dimethyl sulfoxide,419 A-methyl-substituted 4-methyldiethylene-triamines,420 or ethylene- or N- or C-methylated ethylenediamine in aqueous solution have been reported.421 The structure of the silver 1,3-diaminopropane complex, [Ag NH2(CH2)3NH2 ]-C104,422 and complex formation with 1,4-diaminobutane and 1,5-diaminopentane have been reported.423 A dinuclear silver(I) compound with ethylenediamine [(enH)Ag(en)Ag(enH)2]4+ has... 

Similarly, by Schiff-base condensation reactions have been used to generate free cryptands from triamines and dicarbonyls in [2+3] condensation mode. These ligands react with silver(I) compounds to give dinuclear or trinuclear macrocyclic compounds where Ag Ag interactions may be present. Thus, with a small azacryptand a dinuclear complex with a short Ag- Ag distance (55) is found.498 With bigger azacryptand ligands also dinuclear complexes as (56) are achieved but without silver-silver interaction. 65,499-501 A heterobinuclear Ag1—Cu1 cryptate has also been... 

Thia-crown ethers incorporating propan-2-one units and dimeric silver(I) compounds as (176) and other polymeric species have been prepared.1132,1133 Other substituents can be diisopropyl idene groups which form complexes of the type [AgL(PPh3)]OTf (177),1134 pyridazine,1133 phthalazine1136 ligands or even organometallic compounds as ferrocene in (178).1137... 

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