Novel half-sandwich iridium(III) complexes with aminomethyl(diphenyl)phosphine derived from fluoroloquinolones (IrPCp, IrPSf, IrPLm, IrPNr) were being studied as possible anticancer chemotherapeutics with potency higher than that of the other well-known metal-based...

The [Ni(Im)(2)(L-tyr)(2)]·4H(2)O (1) complex was obtained in crystalline form as a product of interaction of L-tyrosine sodium salt, imidazole, and NiSO(4). The X-ray structure was determined, and the spectral (IR, FIR, NIR-vis-UV, HF EPR) and magnetic properties were studied. The Ni(2+) ion is hexacoordinated by the N and O atoms from two L-tyrosine molecules and by two N atoms of imidazole, resulting in a slightly distorted octahedral [NiN(2)N(2)'O(2)] geometry with a tetragonality parameter T = 0.995. The bands observed in the electronic spectra were ascribed to the six spin-allowed electronic transitions (3)B(1g) → (3)E(g) and (3)B(2g), (3)B(1g) → (3)A(2g) and (3)E(g), and (3)B(1g) → (3)A(2g) and (3)E(g). The spin Hamiltonian parameters g, D, and E, which were determined from high-field HF EPR spectra, excellently reproduced the magnetic properties of the complex. Calculation of the zero-field splitting in the S = 1 state of nickel(II) using DFT and UHF was attempted. The biological activity of the complexes has been tested for antifungal and antibacterial effects against Aspergillus flavus, Fusarium solani, Penicillium verrucosu, Bacillus subtilis, Serratia marcescens, Pseudomonas fluorescens, and Escherichia coli.

Three pentacoordinate complexes of the type [Co­(pypz)­X2], where pypz is a tridentate ligand 2,6-bis­(pyrazol-1-yl)­pyridine and X = Cl– (1), NCS– (2), and NCO– (3), have been synthesized, and their structures have been determined by X-ray analysis. The DC magnetic data show a sizable magnetic anisotropy, which was confirmed by high-field high-frequency electron paramagnetic resonance (HF EPR) measurements. Well-resolved HF EPR spectra of high spin cobalt (II) were observed over the microwave frequency range 100–650 GHz. The experimental spectra of both complexes were simulated with axial g tensor components, a very large positive D value, and different E/D ratios. To determine the exact D value for 2 (38.4 cm–1) and 3 (40.92 cm–1), the far-infrared magnetic spectroscopy method was used. Knowledge of the zero field splitting parameters and their signs is crucial in interpreting the single-molecule magnet or single chain magnet behavior. The AC susceptibility data confirm that these complexes exhibit a slow magnetic relaxation under small applied DC field with two (1 and 3) or three (2) relaxation modes.

Herein, we have synthesised and characterised a novel organic–inorganic hybrid crystal, [CH3NH3]2KCr(CN)6 (MACr).

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