Coordination behaviour of Ar-SO 2-N-amino acids toward the Mn(II) ion. Crystal and molecular structure of [Mn(tsgln) 2] and [Mn(tS-DL-α-ala) 2(H 2O)]·2.78H 2O·0.92CH 3OH

Abstract

A series of complexes of Ar-SO 2-N-amino acids (Ar-SO 2 =4-toluensulfonyl- (hereafter abbreviated as tosyl) (ts), benzenesulfonyl (bs); amino acid=glycine (gly), DL-α- and β- alanine (α- and β-ala), asparagine (asn) and glutamine (gin)) with Mn(II) was synthesized and characterized by means of spectroscopic and thermal analyses. For two of them [Mn(ts- α-ala) 2(H 2O)]·2.78H 2O·0.92CH 3OH ( I) and [Mn(tsgln) 2] ( II) the crystal and molecular structure was also determined. I crystallizes in the orthorhombic Pbcn space group, with cell dimensions: a=31.212(3), b=11.248(2), c=9.051(2) Å, Z=4. II crystallizes in the monoclinic C2 space group, with cell dimensions: a=17.490(3), b=5.259(2), c=17.432(2) Å, α=120.70(4)°, Z=2. In both compounds the Mn(II) atom is octahedrally coordinated by six oxygen atoms. In I the amino acid monoanion bridges two Mn atoms through the carboxyl group giving rise to a 1D polymer, the coordination to Mn is completed by two water molecules in a special position. In II each amino acid monoanion bridges two Mn atoms through the carboxyl group and binds a third Mn atom through the carbonyl oxygen of the terminal amide group, giving rise to a 2D polymer.