title: Crystal structures of {[Cu(Lpn)2][Fe(CN)5(NO)]·H2O} n and {[Cu(Lpn)2]3[Cr(CN)6]2·5H2O} n [where Lpn = (R)-propane-1,2-di-amine]: two heterometallic chiral cyanide-bridged coordination polymers.
abstract: The title compounds, catena-poly[[[bis-[(R)-propane-1,2-di-amine-κ(2) N,N']copper(II)]-μ-cyanido-κ(2) N:C-[tris-(cyanido-κC)(nitroso-κN)iron(III)]-μ-cyanido-κ(2) C:N] monohydrate], {[Cu(Lpn)2][Fe(CN)5(NO)]·H2O} n , (I), and poly[[hexa-μ-cyanido-κ(12) C:N-hexa-cyanido-κ(6) C-hexa-kis-[(R)-propane-1,2-di-amine-κ(2) N,N']dichromium(III)tricopper(II)] penta-hydrate], {[Cu(Lpn)2]3[Cr(CN)6]2·5H2O} n , (II) [where Lpn = (R)-propane-1,2-di-amine, C3H10N2], are new chiral cyanide-bridged bimetallic coordination polymers. The asymmetric unit of compound (I) is composed of two independent cation-anion units of {[Cu(Lpn)2][Fe(CN)5)(NO)]} and two water mol-ecules. The Fe(III) atoms have distorted octa-hedral geometries, while the Cu(II) atoms can be considered to be penta-coordinate. In the crystal, however, the units align to form zigzag cyanide-bridged chains propagating along [101]. Hence, the Cu(II) atoms have distorted octa-hedral coordination spheres with extremely long semicoordination Cu-N(cyanido) bridging bonds. The chains are linked by O-H⋯N and N-H⋯N hydrogen bonds, forming two-dimensional networks parallel to (010), and the networks are linked via N-H⋯O and N-H⋯N hydrogen bonds, forming a three-dimensional framework. Compound (II) is a two-dimensional cyanide-bridged coordination polymer. The asymmetric unit is composed of two chiral {[Cu(Lpn)2][Cr(CN)6]}(-) anions bridged by a chiral [Cu(Lpn)2](2+) cation and five water mol-ecules of crystallization. Both the Cr(III) atoms and the central Cu(II) atom have distorted octa-hedral geometries. The coordination spheres of the outer Cu(II) atoms of the asymmetric unit can be considered to be penta-coordinate. In the crystal, these units are bridged by long semicoordination Cu-N(cyanide) bridging bonds forming a two-dimensional network, hence these Cu(II) atoms now have distorted octa-hedral geometries. The networks, which lie parallel to (10-1), are linked via O-H⋯O, O-H⋯N, N-H⋯O and N-H⋯N hydrogen bonds involving all five non-coordinating water mol-ecules, the cyanide N atoms and the NH2 groups of the Lpn ligands, forming a three-dimensional framework.
authors.affiliation: Institute of Physics, University of Neuchâtel, Rue Emile-Argand 11, CH-2000 Neuchâtel, Switzerland.
authors.forename: Olha
authors.initials: O
authors.lastname: Sereda
authors.affiliation: Institute of Physics, University of Neuchâtel, Rue Emile-Argand 11, CH-2000 Neuchâtel, Switzerland.
authors.forename: Helen
authors.initials: H
authors.lastname: Stoeckli-Evans
keywords: (R)-propane-1,2-di­amine; bimetallic; chiral; coordination polymers; crystal structure; cyanide-bridged; hydrogen bonding; three-dimensional framework; two-dimensional network