RATIONAL DESIGN OF A NOVEL INTERCALATION SYSTEM - LAYER-GAP CONTROL OF CRYSTALLINE COORDINATION POLYMERS, ([CU(CA)(H2O)(M)](G))(N) (M=2,G=2,5-DIMETHYLPYRAZINE AND PHENAZINE, M=1,G=1,2,3,4,6,7,8,9-OCTAHYDROPHENAZINE)

New copper(II) intercalation compounds, {[Cu(CA)(H2O)(2)](G)}(n) (H(2) CA = chloranilic acid; G = 2,5-dimethylpyrazine (dmpyz) (1a and 1b) an d phenazine (phz) (2)) have been synthesized and characterized. 1a cry stallizes in the triclinic space group P (1) over bar, with a = 8.028( 2) Angstrom, b = 10.269(1) Angstrom, c = 4.780(2) Angstrom, alpha = 93 .85(3)degrees, beta = 101.01(2)degrees, gamma = 90.04(3)degrees, and Z = 1. 1b crystallizes in the triclinic space group P (1) over bar, wit h a 8.010(1) Angstrom, b = 10.117(1) Angstrom, c = 5.162(1) Angstrom, alpha = 94.40(1)degrees, beta = 97.49(1)degrees, gamma = 112.64(1)degr ees, and Z = 1. 2 crystallizes in the triclinic space group P (1) over bar, with a 8.071(1) Angstrom, b = 11.266(1) Angstrom, c = 4.991(1) A ngstrom, alpha = 97.80(1)degrees, beta = 99.58(1)degrees, gamma = 83.0 2(1)degrees, and Z = 1. For all the compounds, the crystal structures consist of one dimensional [Cu(CA)(H2O)(2)](m) chains and uncoordinate d guest molecules (G). Each copper atom for la, Ib, and 2 displays a s ix-coordinate geometry with the two bis-chelating CA(2-) anions and wa ter molecules, providing an infinite, nearly coplanar linear chains ru nning along the a-direction. Theses chains are linked by hydrogen bond s between the coordinated water and the oxygen atoms of CA(2-) on the adjacent chain, forming extended layers, which spread out along the ac -plane. The guest molecules are intercalated in between the {[Cu(CA)(H 2O)(2)](k)}(t) layers, just like pillars, which are supported with N.. .H2O hydrogen bonding. The guest molecules are stacked each other with an interplanar distance of ca. 3.2 Angstrom along the c-axis perpendi cular to the [Cu(CA)(H2O)(2)](m) chain. The EHMO band calculations of intercalated dmpyz and phz columns show an appreciable band dispersion of phz pi (b(2g) and b(3g)) and dmpyz pi (b(g)), indicative of the im portance of planar pi structure for the formation of the intercalated structure. The distances of O-H---N (guest molecules) fall within the range 2.74-2.80 Angstrom, insensitive to the guest, whereas the interl ayer distances increase in the order 9.25 Angstrom (1b), 10.24 Angstro m (1a), and 11.03 Angstrom (2). The degree in lengthening the distance correlates well with the size of a molecule, indicative of the stabil ity of the 2-D sheet structure and the flexibility of the sheet packin g. The magnetic susceptibilities were measured from 2 to 300 K and ana lyzed by a one-dimensional Heisenberg-exchange model to yield J = -1.8 3 cm(-1), g = 2.18 (1a), J = -0.39 cm(-1), g = 2.14 (1b), and J = -1.8 4 cm(-1), g = 2.18 (2). The absolute value of J is smaller than that v alue for [Cu(CA)](n), which has a planar ribbon structure suggesting t hat the magnetic orbital d(x2-y2) is not parallel to the chloranilate plane. For comparison with phz another type of copper(II) coordination compound, {[Cu(CA)(H2O)](ohphz)}(n) (ohphz 1,2,3,4,6,7,8,9-octahydrop henazine (7)) has also been obtained. 7 crystallizes in the orthorhomb ic space group Cmcm with a = 7.601(2) Angstrom, b = 13.884(2) Angstrom , c = 17.676(4) Angstrom, and Z = 4. Nonplanar ohphz molecules are in between [Cu(CA)(H2O)(2)](m) chains with the N...H2O hydrogen bonding i n a fashion parallel to the chain direction. The copper atom shows a f ive-coordinate square-pyramidal configuration with two CA and one wate r molecule, thus affording no hydrogen bonding links between chains, d issimilar to la, 1b, and 2. The magnetic susceptibilities yield J = -1 0.93 cm(-1) and g = 2.00, comparable to that of the four-coordinate [C u(CA)](n). On this basis both hydrogen bonding and stack capability of a guest molecule is responsible for building the unique intercalated structure such as is seen in 1a, 1b, and 2.