Novel layered structures constructed from iron-chloranilate compounds

Novel hydrogen bond-supported intercalation compounds, {(G)(m)[Fe(CA)(2)(H2 O)(2)]}(n) (CA(2-) = chloranilate, G = guest molecules) have been synthesiz ed and characterized. The compound {(Hpy)[Fe(CA)(2)(H2O)(2)](H2O)}(n) (py = pyridine) (1) crystallizes in the triclinic, space group PT (#2), with a = 9.537(5), b = 13.563(6), c = 9.231(4) Angstrom alpha = 107.18(4), beta = 1 02.33(4), gamma = 102.12(4)degrees V = 1065.9(10) Angstrom(3), and Z = 2. C ompound {(H(2)bipy)[Fe(CA)(2)(H2O)(2)](2)(H2O)(2)}(n) (bipy = 4,4'-bipyridi ne) (2) crystallizes in the triclinic, space group P (1) over bar (#2), wit h a = 9.101(1), b = 10.379(1), c = 12.802(2) Angstrom, alpha = 79.45(1), be ta = 82.67(1), gamma = 66.32(1)degrees V = 1086.8(3) Angstrom(3), and Z = 1 . The structure of 1 consists of mononuclear [Fe(CA)(2)(H2O)(2)](-) anions, Hpy(+) cations and uncoordinated water molecules. Four oxygen atoms of two CA(2-) anions and two oxygen atoms from two water molecules are coordinate d to the iron ion making anionic building blocks of the host layer. The com pound of 2 contains the similar monomeric building blocks, H(2)bipy(2+) cat ions and uncoordinated water molecules. In both the compounds the coordinat ion geometry of the building blocks are distorted octahedron, where two wat er molecules sit on the tr mts position in 1 and on the cis position in 2. In compound 1 the [Fe(CA)(2)(H2O)(2)] anions make a two-dimensional (2-D) l ayer supported by hydrogen bonds. Hpy(+) ions are included in between the l ayers of 1 supported by hydrogen-bonding and electrostatic interaction with the host layers. In compound 2 the coordinated chloranilate rings of [Fe(C A)(2)(H2O)(2)](-) anions are stacked upon each other and make a layer with the help of hydrogen bonds. H(2)bipy(2+) cations are included in between th e layers supported by hydrogen bonding, electrostatic and stacking interact ion with coordinated CA(2-) ions. The Fe-57 Mossbauer spectra of the compou nds show that the oxidation state of iron is 3 with IS = 0.41 (1) and 0.39 mm s(-1) (2); QS = 0.83 (1) and 1.29 mm s(-1) (2) at 296 K, respectively. C ompound 2 shows weak antiferromagnetic interaction over the crystal (theta = -2.3 K). (C) 2000 Elsevier Science S.A. All rights reserved.