Solvothermal syntheses, high- and low-temperature crystal structures, and thermochromic behavior of [1,2-diethyl-3,4,5-trimethyl-pyrazolium]4[Bi4I16] and [1,10-phenanthrolinium][BiI4]•(H2O)

A new iron(II) scorpionate complex, {Fe[HC(3,4,5-Me(3)pz)(3)](2)}(I)(2) (pz=pyrazolyl) (1), and two novel compounds containing low-dimensional poly(iodobismuthate) anions [l,2-Et-2-3,4,5-Me(3)pz](4)[Bi4I16] ([l,2-Et-2-3,4,5-Me(3)Pz](+)=[1,2-diethyl-3,4,5-trimethyl-pyrazolium](+)) (2), and [H(1,10-phen)][BiI4]center dot(H2O) ([H(1,10-phen)](+)=[1,10-phenanthrolinium](+)) (3), have been synthesized and characterized by single crystal X-ray diffraction. Crystals of 2 resulted from the solvothermal reaction of BiI3 and {Fe[HC(3,4,5-Me(3)pz)(3)](2))(I)(2) in an ethanol/water solvent mixture. The anion of this compound is discrete (0-D) and consists of four slightly distorted BiI6 octahedra joined in an edge-sharing arrangement, and the cation is a decomposition/solvent attack product of the iron scorpionate complex. Crystals of 3 resulted from the solvothermal reaction of BiI3, 1,10-phenanthroline, and CuI in an ethanol/water solvent mixture. [H(l,10-phen)][BiI4]center dot(H2O) contains 1-D) chains of BiI6 octahedra and a protonated phenanthroline/water molecule complex. Both 2 and 3 are thermochromic compounds as their colors change, respectively, from orange at 296 K to yellow upon cooling to 100 K and from red-orange at 296 K to orange at 100 K. Crystallographic data at both temperatures were recorded for each sample and are reported here. The crystallographic data indicate that interatomic distances (Bi-I and Bi...Bi) within the inorganic anions change as a function of temperature, and it is believed that these changes are associated with the observation of thermochromism. {Fe[HC(3,4,5-Me(3)pz)(3)](2)}(I)2 (1) crystallizes in the monoclinic space group P2(1)/n with the following lattice parameters at 150(l) K: a=10.8489(5) angstrom, b=17.6642(9) angstrom, c=15.4131(8) angstrom, beta=102.4860(10)degrees. [Et(2)Me(3)pz]4[Bi4I16] (2) and [H(1,10-phen)][BiI4]center dot(H2O) (3) both crystallize in the triclinic space group P (1) over bar with the following lattice parameters for 2 at 296(l) K and 100(l) K, respectively: a=11.2923(4) angstrom, b=13.6412(5) angstrom, c=15.0824(6) angstrom, alpha=78.2090(10)degrees, beta=71.9670(10)degrees, and gamma=67.4020(10)degrees; a=11.0963(7) angstrom, b=13.4158(8) angstrom, c=14.9840(9) angstrom, alpha=79.1450(10)degrees, beta=71.1310(10)degrees, and gamma=68.1360(10)degrees. Lattice parameters for 3 at 296(l) K and 100(1) K, respectively, are as follows: a=7.7590(4) angstrom, b=11.1477(5) angstrom, c=12.0731(6) angstrom, alpha=77.6570(10)degrees, beta=79.1900(10)degrees, and gamma=71.2950(10)degrees; a=7.7000(4) angstrom, b=10.9265(6) angstrom, c=11.9748(7) angstrom, alpha=78.1020(10)degrees, beta=79.9940(10)degrees, and gamma=71.8380(10)degrees. (c) 2007 Elsevier Masson SAS. All rights reserved.