Akademik Veri Yönetim Sistemi
INORGANICA CHIMICA ACTA, cilt.436, ss.7-15, 2015 (SCI-Expanded)
A series of square-planar palladium(II) benzisothiazolinate (bit) of the general type [Pd(bit)(2)L-2] have been prepared and characterized by analytical and spectroscopic methods. Two synthetic routes have been employed, namely reactions of [Pd(bit)(2)]center dot H2O with two equivalents of ligands (L = amine, amide, phosphine) or nucleophile displacement of chloride by benzisothiazolinate starting from trans-[PdCl2L2]. Both routes afford the new complexes in good yields as easily isolated, air and moisture stable, colored solids. The precursor, [Pd(bit)(2)]center dot H2O, is itself prepared in high yields upon reaction of Na[bit] with Na-2[PdCl4] in methanol and the analogous platinum complex, [Pt(bit)(2)]center dot H2O, is similarly prepared from K-2[PtCl4]. It is not clear if these species are mono-or dimeric, and formulation as [M-2(mu-bit)(4)(H2O)(2)] with the four benzisothiazolinate spanning the metal-metal vector and possibly binding through coordination of nitrogen and oxygen is suggested. Diphosphine adducts, cis-[Pd(bit)2{kappa(2)-Ph2P(CH2)(n)PPh2}] (n = 1-4) can be prepared both upon addition of the diphosphine to [Pd(bit)(2)]H2O and from reactions of cis-[PdCl2{kappa(2)-Ph2P(CH2)(n)PPh2}] with two equivalents of Na[bit]. A crystal structure of cis-[Pd(bit)(2) (kappa(2)-dppe)] reveals that the benzisothiazolinate ligands are bonded in a monodentate fashion through nitrogen and this binding mode is proposed for all [Pd(bit)(2)L-2] and [Pd(bit)(2)L] complexes. With dppb (n = 4) a second product is seen by NMR spectroscopy being proposed to be the part-substituted complex cis-[PdCl(bit)(kappa(2)-dppb)], while with dppm (n = 1) two further products are seen spectroscopically, proposed as trans-[Pd(bit)(2)(kappa(1)-dppm)(2)] and (more tenuously) [Pd-2(bit)(4)(dppm)(2)]. The former is also prepared in good yields from reaction of [Pd(kappa(2)-dppm)(2)]Cl-2 with Na[bit]. These studies show that palladium benzisothiazolinate are easily accessed and show good air and moisture stability. (C) 2015 Elsevier B.V. All rights reserved.