Experimental and DFT studies on poly[octa-μ₃-acesulfamato-O,O:N,O′;O′,N:O,O-tetraaquatetrabarium(II)] complex

Abstract

The oxidative addition of B-B bonds of diboranes(4) to late transition metal centres affording bis(boryl)complexes [L n M(BR 2 ) 2 ] [1,2] is of great importance because it constitutes the key step in metal-mediated diboration reactions of unsaturated substrates under both homogeneous [3,4] and heterogeneous [5] conditions. Based on facile oxidative addition of B-Br and B-I bonds to Pt(0) centres [6], we became interested in the reactivity of diboranes(4) Br 2 B 2 R 2 (R = NMe 2 , Mes) towards low-valent phosphine platinum complexes. We have now successfully accomplished the synthesis of two different types of diboranyl (4) , which features a dative bond from the platinum to the second boron atom, resulting in a distorted square-pyramidal geometry of the platinum centre [7]. In course of this reaction the released phosphine PEt 3 reacts with one equivalent of diborane (4) [1] Ishiyama, T., Matsuda, N., Miyaura, N. & Suzuki, A. (1993 O] n The compound crystallizes in the centrosymmetric monoclinic space group P2 1 /c with a = 8.2223(3), b = 18.9945(6), c = 11.7819(4) Å, b = 123.902(2)°a nd Z = 4. The Ba 2+ ion, surrounded by O-and N-atoms, has nine coordination and the complex forms a polymer that extends parallel to the a-axis. The molecular structure is stabilized by O¯H···O and C¯H···O intermolecular hydrogen bonds.The geometric parameters which are obtained from X-ray diffraction and the theoretical parameters for the asymmetric unit which are calculated by using density functional theory (B3LYP) with the 6-31G basis sets are compared. Furthermore, molecular electrostatic potential map and frontier molecular orbital calculations together with experimental and theoretical IR studies were made for this structure.