Synthesis, characterization, X-ray crystallography and antimicrobial activities of new Co(III) and Cu(II) complexes with a pyrazole based Schiff base ligand

Qualitative Guest Sensing via Iron(II) Triazole Complexes

The pyridazine-pyridine triazole-based Rat ligand, L^pydzpy [4-(4-methylphenyl)-3-(3-pyridazinyl)-5-(2-pyridinyl)-1,2,4-triazole], is potentially ditopic. Nevertheless, L^pydzpy is shown herein to exclusively form mononuclear iron(II) complexes, [Fe^II(L^pydzpy)₂(NCE)₂]·solvent, in the presence of coordinating NCE anions (E = S or Se). Specifically, a new family of 10 mononuclear complexes, in which L^pydzpy binds in a monotopic bidentate manner, has been made: two solvent-free complexes, [Fe^II(L^pydzpy)₂(NCS)₂] (1) and [Fe^II(L^pydzpy)₂(NCSe)₂] (2); six solvatomorphs, 1·4CH₃CN, 2·4CH₃CN, 1·2.25CH₃CN, 2·3CH₃CN, 2·tetrahydrofuran, and 2·CHCl₃; and a pair of desolvated polymorphs, 1' and 2'. Seven of them are spin crossover-active, the exceptions being 1, 2, and 2'. This is confirmed by single-crystal X-ray diffraction (XRD) for 1, 2, 1·4CH₃CN, and 2·4CH₃CN and is consistent with variable-temperature optical microscopy observations on single crystals of 1·4CH₃CN and 2·4CH₃CN and on samples of 1' and 2'. Powder XRD, thermogravimetric analysis, and solid-state magnetometry reveal that desolvated 1' and 2' are capable of absorbing and desorbing a range of volatile guests: CH₃CN in both cases and also tetrahydrofuran and CHCl₃ in the case of 2'.

Crystal structure of 1,1′-(butane-1,4-diyl)bis(5-methyl-1H-pyrazole-3-carbaldehyde), C14H18N4O2

C14H18N4O2, monoclinic, P21/c (no. 14), a = 4.4260(9) Å, b = 14.502(4) Å, c = 11.455(3) Å, β = 96.319(5)°, V = 730.8(3) Å3, Z = 2, Rgt(F) = 0.0712, wRref(F2) = 0.1946, T = 296(2) K.

Synthesis, crystal structure, fluorescence and antimicrobial activity of a series of rare-earth complexes based on indolebutyric acid

The antimicrobial activity of a series of rare earth complexes was investigated in detail.