Experimental and theoretical (DFT) studies on poly[octa-μ3-acesulfamato-O,O:N,Oʹ;Oʹ,N:O,O-tetraaquatetrabarium(II)] and poly[octa-μ3-acesulfamato-O,O:N,Oʹ;Oʹ,N:O,O-tetraaquatetrastrontium(II)] complexes

Abstract

Two new one-dimensional coordination polymers of barium(II) and strontium(II)-acesulfamato complexes such as [Ba(C 4 H 4 NO 4 S) 2 (H 2 O)] n (1) and [Sr(C 4 H 4 NO 4 S) 2 (H 2 O)] n (2) have been synthesized and their molecular structures were identified by X-ray diffraction technique. Both barium(II) and strontium(II) complexes crystallize in the centrosymmetric monoclinic space group P12 1 /c1 and barium(II) and strontium(II) ions, which are surrounded by O-and N-atoms, have the coordination number of nine. Each complex forms a structure like a polymer extending parallel to the a-axis. The molecular structures of those complexes were stabilized by O-H···O and C-H···O hydrogen bonds.Besides identifying their crystallographic structures, the geometric parameters were also calculated using density functional theory (B3LYP) with 6-31G base sets for the asymmetric units of the complexes. The calculated geometrical parameters were also compared to the geometric parameters of X-ray diffraction technique. Furthermore, molecular electrostatic potential maps were constructed and frontier molecular orbital calculations were done for the synthesized complexes. The results of the experimental and theoretical IR studies were also compared. Покрај определување на нивните кристални структури, пресметани се и геометриските параметри со помош на теоријата за функционал на електронската густина (B3LYP), користејќи базисни сетови 6-31G за асиметричните единки во комлексите. Пресметаните геометриски † Dedicated to Academician Gligor Jovanovski on the occasion of his 70 th birthday.

Structural and IR-spectroscopic characterization of magnesium acesulfamate

“…1, and the bond distances and angles in the acesulfamate anion are listed in Table 1. These are in accordance with values reported for the alkaline metal salts [4,8], the heavier alkaline-earth salts [10,11] and the thallium(I) salt [9]. Particularly, the short C3-C4 distance of 1.322(4) Å confirms the formal double bond character expected for this link.…”

“…The Mg(II) ion is situated at a crystallographic inversion center in an octahedral environment of water molecules which are coordinated through their oxygen lone pairs [Mg-Ow bond distances of 2.050(2), 2.072(2) and 2.085(2) Å, and Ow-Mg-Ow angles of 91.0(1)°, 91.4(1)° and 89.4(1)°]. This prevents the Mg(II) ion from direct electrostatic interaction with the acesulfamate anion, as it happens in the calcium, strontium and barium salts [10,11]. The ionic [Mg(H 2 O) 6 ] 2+ /Aceinteraction is mediated by hydrogen bonding involving as donors all three independent water molecules and as acceptors the nitrogen 1).…”

“…We could characterize ammonium acesulfamate [7] and have found that the isotypic sodium, rubidium and cesium acesulfamates [8], as well as the corresponding thallium(I) salt [9], are isostructural to one another and to the previously known potassium salt [4]. Also, calcium [10], strontium and barium [11] acesulfamates have recently been prepared and characterized.…”

Structural and IR-spectroscopic characterization of cadmium and lead(II) acesulfamates

“…Concerning simple salts of the anion, apart of the potassium salt [1,6], well known for more than 40 years, some others (NH 4 + [7], Na + , Rb + , Cs + [8], Mg 2+ [9], Ca 2+ [10], Sr 2+ , Ba 2+ [11] and Tl + [12]) have been prepared and characterized only very recently.…”