Dicyanamide complexes

Homo- and heteroleptic complexes of Cd alone and of Cd and Hg with the ligand dicyanamide (dca) N(CN)2-, homologous to cyanamide NCN2-, have been studied in various solvents (formation constants of the complexes [M(dca) ](" 2> (M = Cd, Hg l < n < 4)), with the result that the complexes of Hg are more stable than those of Cd. Otherwise, obviously no studies on the isolated compounds M(dca)2 or on homoleptic complexes derived therefrom have been published. 

Ruthenium(II) Treatment of [Ru(NH3)5(OH2)]2+ or [Ru(NH3)5(acetone)]2+ with L or [RuCl(NH3)5]2+ with zinc amalgam in the presence of L yields [RuL(NH3)5]2+ (L = acetonitrile, benzonitrile,358 substituted benzonitrile,196 358 359 acrylonitrile,360 hydrogen cyanide,36,37 ethyl cyano-formate,361 dicyanamide, malononitrile, substituted malononitrile, tricyanomethanide,362 4-cyano-l-methylpyridinium196). Reaction of a hundred-fold excess of RCHO (R = Ph, Me) with [Ru(NH3)6]2+ under alkaline conditions yields [Ru(NH3)sNCR]2+.363-365 The likely mechanism of this reaction is given in Scheme 12. An alternative route to nitrile complexes is by reaction of [Ru(NH3)sOH2]2+ with aldoximes, e.g. RMeC=NOH, to afford [Ru(NH3 )5 (NCMe)]2 + and... 

A simple synthesis of 1,3,5-trichloro-l A4,2,4.6-thiatriazine (1) is by treatment of sodium or tetraalkylammonium dicyanamide with thionyl chloride.910 Originally, this reaction was described in 1970 and the product was thought to be jV -chloro-A/-(chlorosulfanyl)-/V-cyano-carboximidic chloride.60 The reaction is carried out with a great excess of thionyl chloride in the presence of a catalytic amount of dimethylformamide. The first reaction step consists of the formation of the thionyl chloride-dimethylformamide complex and reaction with the dicyanamide anion. The second step is a further sulfinylation with elimination of sulfur dioxide.32... 

The multicomponent assembly of the tricopper(I) metallostar [(21) Cu(20) 3] (2 from (21), (20) and [Cu(MeCN)4][BF4] in CH2CI2 has been described by Lehn and Baxter. This self-assembly process is the prototype reaction for the construction of a series of heteroleptic multi-nuclear cylindrical species. The related complex [(24) Cu(dppe) 3] has been reported and is of interest as in the reaction of copper(I) with (24), the ligand is reduced to the radical anion (24 ). The dicationic species (25) (only ipso carbon of the phenyl represented) comprises three copper(I) centers and a (24 ) radical anion. The reaction of (18) with [Cr(CO)e] yields the trinuclear star [(18) Cr(CO)4 3] together with dinuclear and mononuclear species. The trinuclear complex with terminal dicyanamide ligands [(18) Co(N(CN)2)2 3] has also been reported and structurally characterized. ... 

Complex supramolecular architectures have been established for dimethyl-thallium(III) derivatives of polyfunctional nitrogen ligands, e.g. the cyanide, the azide, the cyanate, the thiocyanate [177], the dicyanamide, and the tricyanomethide [178], The cyanide, Me2TlCN, 53, contains layers of nearly coplanar CN groups... 

In the dicyanamide, 57, and the tricyanomethide, 58, dimethylthallium(lll) derivatives the structure of the ligands determines the formation of large rings, as part of complex supramolecular architectures. 

Similar dicopper cascade complexes of the caging ligand 14 with encapsulated fiij-cyanamide and dicyanamide bridging anions (Scheme 2.67) have been isolated and structurally characterized in [78]. Para-phenylene analog 7 of this macrobicyclic ligand is reported in [79] to form a H302 -bridged dicopper covalent capsule shown Scheme 2.68. 

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