Preparation and structural organisation of heteroleptic tetraphenylantimony(V) complexes comprising unidentately and bidentately coordinated O,O 0 -dialkyldithiophosphate groups: Multinuclear ( 13 C, 31 P) CP/MAS NMR and single-crystal X-ray diffraction studies Maxim A. Ivanov a , Oleg N. Antzutkin b , Vladimir V. Sharutin c , Alexander V. Ivanov a, * , Antonya P. Pakusina c , Mikhail A. Pushilin d , Willis Forsling b a Institute of Geology and Nature Management, Far Eastern Branch of the Russian Academy of Sciences, 675000 Blagoveschensk, Amur Region, Russia b Division of Chemistry, Lulea ˚ University of Technology, S-97187 Lulea ˚ , Sweden c Blagoveschensk State Pedagogical University, 675000 Blagoveschensk, Amur Region, Russia d Institute of Chemistry, Far Eastern Branch of the Russian Academy of Sciences, 690022 Vladivostok, Russia Received 2 August 2006; accepted 7 February 2007 Available online 12 March 2007 Abstract O,O 0 -dipropyldithiophosphate and O,O 0 -di-iso-butyldithiophosphate (Dtph) tetraphenylantimony(V) complexes of the general for- mula [Sb(C 6 H 5 ) 4 {S 2 P(OR) 2 }] (R = C 3 H 7 , i-C 4 H 9 ) were prepared and studied by means of 13 C, 31 P CP/MAS NMR spectroscopy and single-crystal X-ray diffraction. Distorted octahedral and trigonal bipyramidal molecular structures have been established for prepared complexes. These unexpected structural distinctions between chemically related compounds are defined by the principally different coor- dination modes of O,O 0 -dipropyldithiophosphate and O,O 0 -di-iso-butyldithiophosphate ligands in their molecular structures (i.e., S,S 0 - bidentate chelating and S-unidentately coordinated, respectively). To characterise quantitatively phosphorus sites in both species of dithiophosphate ligands, 31 P chemical shift anisotropy parameters (d aniso and g) were calculated from spinning sideband manifolds in MAS NMR spectra. The 31 P chemical shift tensors for the bidentate chelating and unidentately coordinated dithiophosphate ligands display a profoundly rhombic and nearly axially symmetric characters, respectively. Ó 2007 Elsevier B.V. All rights reserved. Keywords: Heteroleptic dialkyldithiophosphate tetraphenylantimony(V) complexes; Molecular structures; 13 C, 31 P CP/MAS NMR spectroscopy; 31 P chemical shift anisotropy; Single-crystal X-ray diffraction 1. Introduction Organoantimony compounds are of interest as biocides, fungicides, catalyst components and antioxidants [1]. Therefore, syntheses of new organoantimony compounds and studies of their structures and properties are of interest in modern coordination chemistry. Recently, we reported the preparation, heteronuclear ( 13 C, 15 N) CP/MAS NMR and structural studies of polycrystalline heteroleptic N,N- dialkyldithiocarbamate tetra-p-tolylantimony(V) and tetraphenylantimony(V) complexes of the general formulas [Sb(p-CH 3 –C 6 H 4 ) 4 (S 2 CNR 2 )] and [Sb(C 6 H 5 ) 4 (S 2 CNR 2 )], where R = CH 3 ,C 2 H 5 ,C 3 H 7 and R 2 = (CH 2 ) 6 [2–4]. Dis- torted octahedral molecular structures with S,S 0 -bidentate 0020-1693/$ - see front matter Ó 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.ica.2007.02.044 * Corresponding author. Tel.: +07 4162 527232; fax: +07 4162 534618. E-mail addresses: Oleg.Antzutkin@ltu.se (O.N. Antzutkin), vvsharu- tin@rambler.ru (V.V. Sharutin), alexander.v.ivanov@chemist.com (A.V. Ivanov), pumalych@ich.dvo.ru (M.A. Pushilin), Willis.Forsling@ltu.se (W. Forsling). www.elsevier.com/locate/ica Inorganica Chimica Acta 360 (2007) 2897–2904