Phenylbiguanide-p-sulfonic Acid Complexes of Copper II

Two modifications (green and red) of the copper derivative of phenylbiguanide-p-sulfonic acid (A-(amidinoami-dino)sulfanilic acid) are known. Both are formed by the careful neutralization of the acid by ammonia in the presence of copper ion. The two modifications have almost the same magnetic moment and they dissolve in alkali to give the same red solution. Although only a few cis-trans isomers of copper (II) are known, infrared spectra indicate that the two forms of the present complex are cis-trans isomers.  

Phenylbiguanide-p-sulfonic acid is prepared by the usual reaction for the synthesis of Af-substituted biguanides the addition of dicyanodiamide (cyanoguanidine) to 

Phenylbiguanide-p-sulfonic acid forms silky white crystals which are very slightly acid to litmus. The substance is nearly insoluble in cold water and organic solvents such as alcohol, ether, and acetone, but is soluble in strong acids as well as dilute alkalies and ammonia. 

Red-violet modification. A mixture of 2.05 g. (0.008 mol) of phenylbiguanide-p-sulfonic acid and 150 ml. of water is acidified with 1.5 ml. of concentrated hydrochloric acid (35%) and warmed to 60°. To this solution is added 1 g. (0.004 mol) of copper (II) sulfate 5-hydrate dissolved in 10 ml. of water. The resulting solution is then treated with dilute (12%) ammonia water drop by drop imtil the solution becomes just alkaline and the red-violet crystals of the copper complex separate. About 4 ml. of ammonia is required. The crystals are filtered, washed first with 100 ml. of water and finally with 15 ml. of ethanol, and dried in air. Yield 2.2 g. (93% based on copper taken). Anul. Calcd. for [Cu(H03SC6H4C2NsH5)2]-H20 N, 23.59 Cu, 10.71 H2O, 3.04. Found N, 23.66 Cu, 10.61, 10.64 H2O (loss at 90°), 3.0. 

TETRAKISPODO (TRI-n-BUTYLPHOSPHINE)-COPPERP)] AND IODO-(2,2 -BIPYRIDINE)-(TRI-n-BUTYLPHOSPHINE)COPPER(I) 

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See also Phenylbiguanide-p-sulfonic acid complexes of copper(II), synthesis 2... 

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