Triorganoarsenic(V) compounds with internally functionalized oximes: synthetic and spectroscopic aspects of [R 3 As(Cl)L], [R 3 As(OH)L] and [R 3 AsL 2 ]: crystal and molecular structure of [Pr 3 i AsOH]  Cl  Anjali Gupta a , Rajnish K. Sharma a , Rakesh Bohra a, *, Vimal K. Jain b , John E. Drake c , Michael B. Hursthouse d , Mark E. Light d a Department of Chemistry, University of Rajasthan, Jaipur 302004, India b Novel Materials and Structural Chemistry Division, Bhabha Atomic Research Center, Mumbai 400085, India c Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ont., Canada N9B 3P4 d Department of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK Received 13 September 2002; accepted 15 November 2002 Abstract Triorganoarsenic(V) oximates of the type [R 3 As{ON /C(Me)Ar} 2 ](1) (R /Pr i , Bu i ; Ar /C 5 H 4 N-2, C 4 H 3 O-2) are formed by the reactions of R 3 AsCl 2 with the sodium salts of internally functionalized oximes in 1:2 molar ratio in anhydrous benzene. The redistribution products [R 3 As(X){ON /C(Me)Ar}] (2) (X /Cl, Br, OH) are obtained by treatment of 1 with equimolar R 3 AsX 2 . [Pr 3 i As(OH){ON /C(Me)C 5 H 4 N-2}] may also be obtained by the reaction of Pr 3 i As(OH) 2 with the corresponding oxime in 1:1 molar ratio. All of these complexes are characterized by IR and NMR ( 1 H and 13 C) spectroscopy and elemental analyses. Controlled hydrolysis of a representative monochloro-complex [Pr 3 i As(Cl){ON /C(Me)C 4 H 3 O-2}] yields crystals of Pr 3 i As(OH)Cl in which single crystal X-ray diffraction indicates that there is a distorted tetrahedral environment around arsenic. # 2003 Published by Elsevier Science B.V. Keywords: Trialkylarsenic(V); Oximes; NMR; X-ray 1. Introduction There has been a renewal of interest in organoarsenic compounds [1] arising from their wide ranging applica- tions, which include their use as precursors for chemical vapor deposition [2] and as versatile ligands, along with their biocidal/medicinal aspects. The trivalent com- pounds show considerable structural diversity, which is extended by the presence of a stereochemically active lone pair [1]. By contrast, pentavalent compounds, with the exception of tetraorganoarsonium derivatives, often adopt a trigonal bipyramidal geometry [3  /7]. Internally functionalized oximes are known to stabi- lize diverse stereochemistries [8  /10]. There have been several investigations on oximates of arsenic(III) [11 /15] but studies with arsenic(V) are scanty [16]. In view of this and in persuance of our work on organometallic compounds of Group 15, we have prepared triorga- noarsenic(V) compounds derived from internally func- tionalized oximes. 2. Results and discussion The reaction of R 3 AsCl 2 with the sodium salt of 2- heteroaryl methylketone oxime in 1:2 molar ratio yields [R 3 As{ON /C(Me)Ar} 2 ](1) [R /Pr i , Bu i ; Ar /C 5 H 4 N- 2, C 4 H 3 O-2]. Compounds 1 on treatment with one equivalent of R 3 AsX 2 give the redistribution products [R 3 As(X){ON /C(Me)Ar}] (2) (X /Cl, Br or OH). Reactions involving halide derivatives take place in- stantaneously, whereas the corresponding redistribution reaction of [Pr 3 i As{ON /C(Me)C 5 H 4 N-2} 2 ] with Pr 3 i A- * Corresponding author. Journal of Organometallic Chemistry 667 (2003) 61  /65 www.elsevier.com/locate/jorganchem 0022-328X/02/$ - see front matter # 2003 Published by Elsevier Science B.V. doi:10.1016/S0022-328X(02)02126-5