New manganese (II) 2d-polymer with deprotonated hydroxytetrazine bridges

Кискин, М. А.; Сидоров, А. А.; Фомина, И. Г.; Rusinov, Gennady L.; Ишметова, Р. И.; Александров, Г. Г.; Shvedenkov, Yu. G.; Доброхотова, Ж. В.; Новоторцев, В. М.; Чупахин, О. Н.; Еременко, И. Л.; Моисеев, И. И.

doi:10.1016/j.inoche.2005.03.005

Cited by 15 publications

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References 10 publications

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“…This motif was found in many other compounds with varying Mn II and Mn III oxidation states. [91][92][93][94][95][96][97][98][99][100][101][102][103][104][105][106][107] Slow hydrolysis of a mononuclear compound [MnBr(R 2 dbm) 2 ] (where Hdbm = dibenzoylmethane) gives [Mn III 6 O 4 Cl 4 (R 2 dbm) 6 ] (R = Me, 11; Et, 12). 108 The structure of 11 (Fig.…”

Section: Methodsmentioning

confidence: 99%

Structural motifs and topological representation of Mn coordination clusters

2010

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Polynuclear coordination clusters have become of particular interest in recent times as a result of their relevance to bioinorganic chemistry and to the special area of molecule-based magnetic materials where cluster compounds behave as single-molecule magnets (SMMs). In this review we have focused on describing Mn coordination cluster complexes. Adopting our topological approach for the description of coordination clusters we present a means of classifying the structural motifs found in manganese clusters which range in nuclearity from 5 to 84, as well as some representative heterometallic Mn-M (M = K, Na, Ca, Sr, Ln) cluster complexes that have been reported. This sheds new light on the classification of the types of core structure accessible which, in turn, provides a useful means for developing the so-far missing magneto-structural correlation algorithm for these finite 0-D systems (212 references).

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Section: Methodsmentioning

confidence: 99%

Structural motifs and topological representation of Mn coordination clusters

2010

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“…3,6 Bis(3,5 dimethylpyrazol 1 yl) 1,2,4,5 tetrazine and its derivatives are promising ligands. [2][3][4][5] In the present work, taking iso lated dimeric structures as examples, we have shown that structural distortions in the coordination site cause signif icant changes in the magnitude of the effective magnetic moment even in the absence of exchange interactions be tween the 3d metal (Cu II and Co II ) ions.…”

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confidence: 89%

Synthesis, structures, and magnetic properties of crystals of dinuclear copper(II) and cobalt(II) complexes with 3-(3,5-dimethylpyrazol-1-yl)-6-R-1,2,4,5-tetrazines

et al. 2010

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Dinuclear complexes of Cu II with 3 (3,5 dimethylpyrazol 1 yl) 6 (2 hydroxyethylami no) 1,2,4,5 tetrazine (1) and Co II with 3 (3,5 dimethylpyrazol 1 yl) 6 (piperidin 1 yl) 1,2,4,5 tetrazine (2) were synthesized and structurally characterized, and the magnetic (SQUID) and resonance (EPR) properties of van der Waals crystals based on these complexes were studied. Unusual behavior of the effective magnetic moment μ eff (T) is observed at T < 60 K. A nonmonotonic increase in μ eff (Т) for 1 (~6 %) and a 20% reduction of μ eff (Т) for 2 have a common origin and are due to the influence of spin orbital coupling on the character of the splitting between the t 2g and e g levels of the central ion. Distortions of the coordination site "switch on" a positive (1) or negative (2) contribution of the orbital magnetic moment near 6 K. Irreversible temperature behavior of μ eff (T) in the heating and cooling regimes in the vicinity of 60 K suggests that the character of structural distortions and the magnetic properties are related to ligand geometry. This factor plays a significant role in crystal engineering of magnetoactive structures with polynitrogen ligands.Design of polyfunctional magneto active materials and molecular magnetics based on paramagnetic complexes has become one of the most rapidly developing fields of interdisciplinary research involving modern chemical sci ence and physics of magnetic phenomena. 1 Polynitrogen heterocycles are promising molecular spacers between paramagnetic metal ions for the assembly of high spin blocks. In particular, of interest are polydentate tetrazine ligands where the coordination site geometry can be con trolled by electronic and steric effects; this is the reason for the search for tunable spin transitions (crossovers) in the metal chelate structures based on them. 3,6 Bis(3,5 dimethylpyrazol 1 yl) 1,2,4,5 tetrazine and its derivatives are promising ligands. 2-5 In the present work, taking iso lated dimeric structures as examples, we have shown that structural distortions in the coordination site cause signif icant changes in the magnitude of the effective magnetic moment even in the absence of exchange interactions be tween the 3d metal (Cu II and Co II ) ions. Results and DiscussionThe reactions of Cu II chloride with 3 (3,5 dimeth ylpyrazol 1 yl) 6 (2 hydroxyethylamino) 1,2,4,5 tetra zine and Co II chloride with 3 (3,5 dimethylpyrazol 1 yl) 6 piperidino 1,2,4,5 tetrazine in acetonitrile on heating resulted in crystalline complexes 1 and 2, respectively (Schemes 1 and 2).The structures of the complexes (Figs 1 and 2) were proved by elemental analysis, IR spectroscopy, and X ray diffraction analysis. The IR spectra of complexes 1 and 2 in the absorption regions of the 3,6 dimethylpyrazole sub stituent and tetrazine ring are significantly different from those of the starting tetrazines; this confirms the conclu sion that both fragments are involved in the coordination to the metal atoms. 6 Indeed, in both cases X ray studies revealed the formation of chlorine bridged dinuclear c...

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