ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Condensation of keto and enol forms of acetone in reaction with copper-2 ions and ammonia

F. Hanic and M. Serátor

Institute of Inorganic Chemistry, Slovak Academy of Sciences, Bratislava

Abstract: By the introduction of gaseous NH₃ into Cu(NO₃)₂ soln. in Me₂CO, a condensation takes place which results in the formation of a chelate compd. Cu(II)bis(2-imino-4-aminomethylpentane) nitrate (I) according to the reaction 2Me₂CO + 2CH₂:C(OH)Me + Cu²⁺ + 4NH₃ .dblharw. [Cu(MeC(:NH)CH₂C(NH₂)Me₂)₂]²⁺ + 4H₂O. I is composed of crystals of violet color with the lattice parameters a 7.10 ± 0.03, b 14.63 ± 0.04, c 9.24 ± 0.02 A., β = 99° 21', and space group P21/c,N = 2,Dexp = 1.448 g./cc. The Cu atom is a sq. plane coordinated by 4 amine and imine groups at the distances Cu-NH 1.98 and Cu-NH₂ 2.01 A. Two NO3 groups complete the octahedral coordination of the Cu atom with interat. distances Cu-O 2.75 A. A significant difference exists between the bond lengths C:NH and C.sbd.NH₂, which is 1.30 and 1.51 A. In the crystal structure, the complex ions are bonded with H. Also, NO₃ groups participate on H bonds. The violet color of crystals is caused by Cu(II) coordinated by 4 peptide N atoms. The structure of the complex was proved by x-rays analysis. The chelate bonds cause the relative stability of I against the hydrolysis.

Full paper in Portable Document Format: 188a572.pdf (in Slovak)

Chemical Papers 18 (8) 572–583 (1964)