Synthesis and Structural Characterization of Bis[(cyclohexylamino)pent-2-en-4-onato]-Chromium(II)

Abstract

Addition of one equivalent of CrI2 to two equivalents of lithium cyclohexylamino-pent-2-en-4-onate results in bis[(cyclohexylamino)pent-2-en-4-onato]-chromium(II). Crystallization in diethylether reaction solvent forms the hemi-etherate A with the asymmetric unit showing two target compounds and one molecule of cocrystallized diethylether in the P-1 space group with crystal cell parameters a = 12.931(4) A, b = 13.207(4) A, c = 16.104(5) A, α = 66.559(5)°, β = 77.670(5)°, γ = 81.562(5)°, V = 2,459.1(14) A3 and Z = 4. Drying A in vacuo and recrystallization in pentane yields a nonsolvated crystalline phase B with an asymmetric unit displaying only one molecule of the target compound in the P21/c space group with crystal cell parameters a = 14.290(7) A, b = 14.082(7) A, c = 11.246(6) A, β = 94.807(8)°, V = 2,255.1(19) A3 and Z = 4. A Cr(II) complex supported by two β-enaminoketiminato ligands, bis[(cyclohexylamino)pent-2-en-4-onato]-chromium(II), has been synthesized and has been structurally characterized in two different crystal phases.