title: One-dimensional collective electronic effects in the helically stacked Cs2[Ni(CN)4].H2O and Cs2[Pt(CN)4].H2O: X-ray structure, polarized specular reflectance, and ZINDO calculations.
abstract: The X-ray structure of Cs(2)[Ni(CN)(4)].H(2)O and the polarized single-crystal UV absorbance spectra of Cs(2)[Ni(CN)(4)].H(2)O and Cs(2)[Pt(CN)(4)].H(2)O are presented. The two complexes are isostructural, with helical arrangements of M(CN)(4)(2)(-) ions in which there is moderate metal-metal electronic perturbation resulting in a spectral red shift from solution in the UV absorbance spectra. In addition, we have modeled the nickel system with a ZINDO calculation of a three-molecule segment of the helix and have found remarkably good agreement with experiment, including excellent reproduction of the red shift. Crystal data are as follows: Cs(2)[Ni(CN)(4)].H(2)O, hexagonal, space group P6(1), a = 9.5260(10) A, c = 19.043(2) A, V = 1496.5(3) A(3), T = 100 K, Z = 6, 4335 observed data, R = 0.016, R(w) = 0.034.
authors.affiliation: Department of Chemistry, Principia College, Elsah, Illinois 62028, USA.
authors.forename: Jeffrey B
authors.initials: JB
authors.lastname: Cornelius
authors.forename: Robert M
authors.initials: RM
authors.lastname: Trapp
authors.forename: Terry J
authors.initials: TJ
authors.lastname: Delord
authors.forename: Frank R
authors.initials: FR
authors.lastname: Fronczek
authors.forename: Steven F
authors.initials: SF
authors.lastname: Watkins
authors.forename: Jill Jasin
authors.initials: JJ
authors.lastname: Orosz
authors.forename: Ronald L
authors.initials: RL
authors.lastname: Musselman