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The main aim of our study is to investigate various types of hybrid systems with a paramagnetic iron (III) ion as a core and photoactive derivatives of carbazole at the periphery. We have synthesized a variety of biligand coordination compounds with the composition [FeL2]A (where L is 2‐[2‐[(E)‐[4‐[4‐(3,6‐di‐tert‐butylcarbazol‐9‐yl)benzoyl]oxy‐2‐phenolate]methyleneamino]ethylamino]ethyl 4‐(3,6‐di‐tert‐butylcarbazol‐9‐yl)benzoate, A− is NO3− (I), Cl− (II), PF6− (III)). These systems were studied by superconducting quantum interference device (SQUID) magnetometry and X‐band electron paramagnetic resonance (EPR) spectroscopy. Magnetic measurements revealed mixed spin states (high spin [HS], low spin [LS]) of Fe (III) ions at room temperatures. Estimates of the corresponding spin contributions were made. It was found that all samples exhibit AFM exchange interactions between iron (III) ions. The ground spin state at 2.0 K was established and analyzed. EPR measurements confirmed the HS states of iron (III) and revealed two types of them: with weak distorted and strong low‐symmetry octahedral crystal fields. [ABSTRACT FROM AUTHOR]

In this study, crystals of the hybrid layered structure, combined with Fe(III) Spin-Crossover (SCO) complexes with metal-dithiolate anionic radicals, and the precursors with nitrate and iodine counterions, are obtained and characterized. [Fe(III)(3-OMe-Sal2trien)][Ni(dmit)2] (1), [Fe(III)(3-OMe-Sal2trien)]NO3·H2O (2), [Fe(III)(3-OMe-Sal2trien)]I (3) (3-OMe-Sal2trien = hexadentate N4O2 Schiff base is the product of the condensation of triethylenetetramine with 3-methoxysalicylaldehyde; H2dmit = 2-thioxo-1,3-dithiole-4,5-dithiol). Bulk SCO transition was not achieved in the range 2.0–350 K for all three compounds. Alternatively, the hybrid system (1) exhibited irreversible segregation into the spatial fractions of Low-Spin (LS) and High-Spin (HS) phases of the ferric moiety, induced by thermal cycling. Fractioning was studied using both SQUID and EPR methods. Magnetic properties of the LS and HS phases were analyzed in the framework of cooperative interactions with anionic sublattice: Anion radical layers Ni(dmit)2 (1), and H-bonded chains with NO3 and I (2,3). LS phase of (1) exhibited unusual quasi-two-dimensional conductivity related to the Arrhenius mechanism in the anion radical layers, ρ||c = 2 × 105 Ohm·cm and ρ⊥c = 7 × 102 Ohm·cm at 293 K. Ground spin state of the insulating HS phase was distinctive by ferromagnetically coupled spin pairs of HS Fe3+, S = 5/2, and metal-dithiolate radicals, S = 1/2. [ABSTRACT FROM AUTHOR]

The behavior of 4-thienyl substituted pyrimidine ligands (L 1–3 ) has been studied for the series of their reactions with various salts of 3d metals (Co, Zn, Ni, Cu) and platinoids (Pt, Pd). In particular, mononuclear Co(OTf) 2 (L 1–3 ) 2 (H 2 O) 2 (MeCN) 2 ( 1 ), binuclear Co 2 (Piv) 2 (L 1–3 ) 4 ( 2a , b ), Cu 2 (Piv) 2 (L 1–3 ) 2 ( 5a , b ), heterometallic polynuclear Li 2 Co 2 (Piv) 6 (L 1–3 ) 2 ( 4 ) and chelate [(L 1 )Pd(OAc)] 2 ( 6 ) complexes have been obtained. The structures of all complexes have been established by X-ray diffraction. Also magnetic properties of coordination compounds 1 , 2 , 4 and 5 have been studied in details. In particular, mononuclear Co(II) complexes 1 and 4 proved to exhibit paramagnetism with large positive zero-field splitting parameters. Dinuclear Co(II) complexes 2a , b show weak antiferromagnetic interactions. Dinuclear Cu(II) complexes 5a , b demonstrate strong antiferromagnetic superexchange interactions via four carboxylate bridges. The systems 2a , b and 5a , b are isolated as exchange coupled dimers. [ABSTRACT FROM AUTHOR]

The reaction of [Fe(iii)(CN)6]3− with neutral [Mn(salpn)(H2O)C(CN)3] (salpn: N,N′-propylenebis(salicylideneiminato)) (1) produces two new heterometallic complexes [{MnIII(salpn)(H2O)}2{MnIII(salpn)(H2O)0.7(CH3OH)0.3}2FeII(CN)6]·n(H2O/CH3OH) (2) and [{MnIII(salpn)}4{MnIII(salpn)(H2O)}2FeII(CN)6]{C(CN)3}2·4H2O (3), which are characterized by single-crystal X-ray diffraction. In this reaction, the [C(CN)3]− ligand reduces Fe(iii) to Fe(ii). Complex 3 can be prepared directly using hexacyanoferrate(ii). One more complex containing the hexacyanoferrate(ii), [{MnIII(salpn)(CH3OH)0.67(H2O)0.33}6FeII(CN)6]{ClO4}2·8H2O (4), is obtained in the reaction of [Fe(ii)(CN)6]4− with the cationic complex [Mn2(salpn)2(H2O)2](ClO4)2. The iron(ii) centers in the complexes 2 and 4 are linked via cyano-bridges with the four and six [MnIII(salpn)]+ fragments, respectively. The structure of 3 consists of the cyano-bridged [MnIII6FeII] repeating units linked by double phenolate bridges into a one-dimensional polymeric chain. The magnetic properties of 3 indicate a ferromagnetic coupling between MnIII centers in the double phenolate-bridged [MnIII(salpn)]2 dinuclear subunits. Quantum calculations within the Heisenberg–Van Vleck model are performed giving the exchange constant J = 0.64 cm−1 and the zero-field splitting parameter D = −3.5 ± 0.5 cm−1. The ac-susceptibility obeys the Arrhenius law with the activation energy Ea = 11.89 cm−1. [ABSTRACT FROM AUTHOR]

Abstract: New tetranuclear Cu(II) complex [Cu4(L)4]·MeCN (1) with 2,6-di(5-trifluoromethyl-1H-pyrazol-3-yl)pyridine (H2L) was synthesized. It has been shown that treatment of 1 with selected aza-ligands (pyridine, 2,2′- and 4,4′-bipyridyl, 2,3,5,6-tetra-(pyridine-2-yl)pyrazine, 2,2′;6′,2″-terpyridine and 1,4-diazabicyclo[2.2.2]octane) leads to formation of other Cu(II) complexes with different nuclearity: [Cu(L)py2] (2), [Cu(L)(2,2′-bpy)] (3), [Cu(L)2(tppz)]·THF (5), [Cu(L)tpy]·C6H5CN (4), {[Cu2(L)2(4,4′-bpy)2]·(C6H5CH3)·MeCN} n (6) and {[Cu(L)DABCO]·2MeCN} n (7). Obtained compounds were characterized by IR spectroscopy, X-ray crystallography data, EPR and SQUID magnetic measurements. [Copyright &y& Elsevier]

Abstract: The first heterometallic chain cluster {[Mn4(hmp)6(NO3)2FeNO(CN)5·4CH3CN} n (1) based on the [Mn4(hmp)6] SMM has been synthesized. 1 has one-dimensional chain structure: the [Mn4(hmp)6] units are linked via CN-groups of nitroprusside anions. Its magnetic and relaxation properties and low temperature IR spectra under light irradiation have been investigated. The ferromagnetic exchange constants have been calculated. [Copyright &y& Elsevier]

Correction for ‘Heterometallic complexes combining [MnIII(salpn)]+ and [Fe(CN)6]4− units as the products of reactions between [MnIII(salpn)(H2O)C(CN)3] and [Fe(CN)6]3−/4−’ by Vyacheslav A. Kopotkov et al., New J. Chem., 2014, 38, 4167–4176. [ABSTRACT FROM AUTHOR]