Thermally-Accessible Lattice Strain and Local Pseudo Jahn-Teller Distortion in Various Dimensional CuII-MIII Bimetallic Cyanide-Bridged Assemblies

Abstract

(3), were prepared and characterized structurally. Crystal structures were determined at 263 and 100 K for 1 and 2, while at 299 and 100 K for 3. Thermally-accessible lattice strain resulted in decreasing cell volume of 1.66, 1.06, and 4.1 % for 1-3, respectively. Large thermally-accessible structural change but small pseudo Jahn-Teller elongation at constant temperature could be found in both the long chain of the ladder structure for 3 and the monocuclear Cu II moieties for 1 and 2. In addition, novel mixing of ferromagnetic and antiferromagnetic interactions at low temperature was observed for 3. The correlations between dimensionality of cyanide-bridges and thermally-accessible structural changes distortion associated with Jahn-Teller distortion are also discussed by comparing with several known systems.

Novel Thermally-Accessible Structural Distortion and Lattice Strain of a Chiral Cyanide-Bridged Cu (II)-Ni (II) Complex

“…Similar consideration may be valid for pseudo Jahn-Teller distortion systems of lower symmetry than exact O h symmetry containing different ligands. However, to our knowledge based on a series of investigation about the related compounds showing JahnTeller distortion [18,19], we have never observed thermally accessible structural change opposite tendency against temperature dependence. In this way, both Jahn-Teller contraction in a crystal lattice and elongation on cooling (NTE be- havior about a specific Jahn-Teller distorted bond) may be difficult to find for actual crystalline materials.…”

“…Whereas Cu1-N1 and Cu1-N3 i bonds are long (within a normal range for Cu-N bond distances of Jahn-Teller elongation) and characteristic long axial bonds linked by NC groups. The T values denote tetragonality of distorted octahedral Cu coordination geometry whose definition is T = in-plane Cu-N bond distances / axial Cu-N bond distances [18,19].…”

Isotope Effect and Lanthanide Contraction for 3d-4f Cyanide-Bridged Complexes Exhibiting Negative Thermal Expansion

“…Indeed, extremely long semi-coordination bonds of Cu(II) complexes [18][19][20][21][22] sometimes have potential advantage to form flexible crystals against external temperature changes, which is anisotropic along the Jahn-Teller axis [23][24][25]. However, the present systems show anisotropically negative thermal expansion caused by not coordination bonds around lanthanide nor iron atoms but intermolecular hydrogen bonds with isotope effect for the first time.…”

Observation of Long-Range Vicinal Effect in Chiral Cu(II)-Cr(VI) or Cu(II)-W(VI) Bimetallic Coordination Polymers

“…conventionally induced CD of many supramolecular assemblies [4,5]. As for chiral coordination polymers, thermally-accessible lattice strain and local pseudo Jahn-Teller distortion of [CuL 2 ] 3 [M(CN) 6 ] 2 · 4H 2 O (L = trans-cyclohexane-(1R, 2R)-diamine; M = Cr, Co, and Fe) [6] have been reported.…”