PoIyhedm Vol. 6, No. 6, pp. 137~1381,1987 Printed in Great Britain 0277~5387/87 S3.00+.00 0 1987 Pergamon Jollmala Ltd zyxwvutsr COPPER AND IRON(III) COMPLEXES OF N-NITROSO-N- ALKYLHYDROXYLAMINES, AND THE X-RAY CRYSTAL STRUCTURES OF BIS(N-NITROSO-N- ISOPROPYLHYDROXYLAMINATO)COPPER(II) AND TRIS(iV-NITROSO-lV-PROPYLHYDROXYLAMINATO)IRON(III) MICHAEL H. ABRAHAM, JOSEPH I. BULLOCK,* JOHN H. N. GARLAND, ANDREW J. GOLDER, GRAHAME J. HARDEN, LESLIE F. LARKWORTI-IY,* DAVID C. POVEY, MICHAEL J. RIEDL and GALLIENIJS W. SMITH Department of Chemistry, University of Surrey, Guildford GU2 5XH, U.K. (Received 1 September 1986 ; accepted 5 December 1986) Abstract-N-nitroso-N-alkylhydroxylamines have been prepared by hydrolysis of the mix- ture obtained by reaction of nitric oxide with Grignard reagents, and stabilized as their copper(I1) or iron(II1) complexes, Cu(RN,O,), and Fe(RN202)3, where R is, for example, Me, Et, Pri, Bu’““, Ph, r&H’ 7 or n-C12H2,. The complexes have been characterized by analytical, magnetic and spectroscopic measurements. By single-crystal X-ray methods Cu(PriN202)2 has been found to be trans-planar and Fe(PfN202), has a facial octahedral structure ; in each complex the N-G bond lengths are equal with no significant variation between the copper and iron complexes. The action of nitric oxide on alkyl compounds of diamagnetic metal atoms usually yields’-l6 the corresponding N-nitroso-N-alkylhydroxylamine derivative [eqn (l)] : R-M+2NO + (RN,O,)M. (1) As with cupferron (R = phenyl) complexes,‘7-‘9 the hydroxylamate ligand is chelated and coordinates through the two oxygen atoms in the X-ray cry- stallographic structures reported8,‘o*1‘*‘3*‘6’9 to date. Diamagnetic metals in eqn (1) include zinc, ‘~~3 ’ 2 magnesium, 2-6 cadmium,2 boron, ’ altinium,2~7~8 gallium,’ zirconium,9*‘o tung- sten,“*‘2 copper(I),12 niobium,‘3,‘4 tantalum,‘3*14 titanium,‘* ’ ’ rhenium(II1) ’ 6 and rhodium(I). ’ 2 For some paramagnetic metal ions, for example, van- adium(IY),‘4 and titanium(III),‘4 the N-nitroso-N- alkylhydroxylamine derivatives cannot be prepared directly through eqn (1) while the reaction” of.a low-valent cobalt nitrosyl with an alkyl halide afforded the nitrosoalkane complex. yhnagnesium bromide followed by hydrolysis gave the free acid N-nitroso-N-phenylhydroxylamine (cupferron), identified because its reactions were the same as those of the product2’ obtained by the action of nitrous acid on N-phenylhydroxylamine. The free acid could not be isolated on hydrolysis of the nitric oxide-methyhnagnesium iodide reaction mixture, but Sand and Singer3 did obtain a copper(I1) complex, Cu(MeN202)2, on treatment of the prod- uct with copper(I1) oxide. There are scattered ref- erences to copper(I1) complexes of various other N- nitroso-N-alkylhydroxylamines, but little other than their preparation’*3*‘,9*‘2 and fungicidal properties22 have been reported. We present here a convenient route to N-nitroso- N-alkylhydroxylamine derivatives of copper(B) and iron(II1) which is based on the early work of Sand and Singer.3 As far as we know complexes of iron(II1) have not been characterized previously. Chemical identification of the products in eqn (1) was first carried out by Sand and Singer.3 They showed that the action of nitric oxide on phen- EXPERIMENTAL Preparation of the complexes The ligands were fist isolated as the magnesium complexes from the appropriate Grignard reagent. 375 *Authors to whom correspondence should be addressed. 1