@article{KozlevcarMateJaglicicetal.2009, author = {Kozlevcar, Bojan and Mate, Elizabeta and Jaglicic, Zvonko and Glažar, Lea and Golobic, Amalija and Strauch, Peter and Moncol, Jan and Kitanovski, Nives and {\`e}egedin, Primož}, title = {A small methanoato ligand in the structural differentiation of copper(II) complexes}, issn = {0277-5387}, doi = {10.1016/j.poly.2009.05.066}, year = {2009}, abstract = {Several copper(II) methanoato complexes, namely mononuclear [Cu(O2CH)(2)(2-mpy)(2)] (1) (2-mpy = 2- methylpyridine), binuclear [Cu-2(mu-O2CH)(4)(2-mpy)(2)] (2), and the polynuclear {[Cu(mu-O2CH)(2)(2-mpy)(2)] [Cu-2(mu- O2CH)(4)]}(n) (3) and {Na-2[Cu(mu-O2CH)(2)(O2CH)(2)][Cu-2(mu-O2CH)(4)]}(n) (4), have been synthesized. The mononuclear complex I is formed by two asymmetric chelate methanoate anions and two 2-methylpyridine molecules, giving a highly distorted 'elongated octahedral' coordination sphere. Complex I decomposes outside the mother-liquid, transforming into a regular isolated binuclear paddle-wheel complex 2 with four intra-binuclear bridging methanoates and two axial 2-mpy ligands. The polynuclear complex 3 is formed of alternate mononuclear and binuclear building blocks resembling the central cores of I and 2, but with significant differences, especially for the methanoates of the mononuclear units. The oxygen atom of the mononuclear unit in the octahedral axial position in 3 is simultaneously coordinated to the axial position of the binuclear paddle-wheel central core, thus enabling a chain type of structure. A chain of alternate mononuclear and binuclear building blocks, as in the neutral compound 3. are found as well in the ionic polymeric compound 4, though two types of bridges are found in 4, while there is only one type in 3. Namely, the axial position of the octahedral mononuclear unit in 4 is occupied by the methanoate oxygen atom that is already a part of the binuclear paddle-wheel unit, while one equatorial methanoate from the mononuclear unit serves as a triatomic bridge to the axial position of the binuclear building block. A very strong antiferromagnetic interaction is found for all the complexes with the paddle-wheel building blocks [Cu-2(mu-O2CH)(4)] 2-4 (-2J = 444-482 cm(-1)), attributed to the methanoate intra-binuclear bridges. On the other hand, this strong antiferromagnetism, found already at room temperature, reduces the intensity of the EPR S = 1 spin signals reported for the isolated paddle-wheel complex 2. For the polymeric 3, only the spin S = 1/2 signals are found in the EPR spectra, and they are assigned to the mononuclear building blocks. No signals with a clear origin are however seen in the room temperature EPR spectrum of the polymeric analogue 4, only the S = 1/2 signals in the low temperature spectra. This feature is suggested to be due to a specific influence between the adjacent S = 1 (binuclear) and S = 1/2 (mononuclear) species via their bridges.}, language = {en} } @article{KozlevcarGamezdeGelderetal.2011, author = {Kozlevcar, Bojan and Gamez, Patrick and de Gelder, Rene and Jaglicic, Zvonko and Strauch, Peter and Kitanovski, Nives and Reedijk, Jan}, title = {Counterion and solvent effects on the primary coordination sphere of copper(II) Bis(3,5-dimethylpyrazol-1-yl)acetic acid coordination compounds}, series = {European journal of inorganic chemistry : a journal of ChemPubSoc Europe}, journal = {European journal of inorganic chemistry : a journal of ChemPubSoc Europe}, number = {24}, publisher = {Wiley-Blackwell}, address = {Malden}, issn = {1434-1948}, doi = {10.1002/ejic.201100410}, pages = {3650 -- 3655}, year = {2011}, abstract = {Four copper(II) coordination compounds with the neutral ligand bis(3,5-dimethylpyrazol-1-yl)acetic acid (Hbdmpza, C(12)H(16)N(4)O(2)) and its anionic form (bdmpza(-)), namely [Cu(Hbdmpza)(2)](HSO(4))(2) (1), [Cu(Hbdmpza)(2)]Cl(2) (2), [Cu(bdmpza)(2)](CH(3)COOH)(H(2)O) (3), and [Cu(bdmpza)(2)][Cu(2)(O(2)CCH(3))(4)] (4) have been synthesized starting from different metal salts. All the compounds have been fully characterized by physical and analytical methods. In addition, a single-crystal XRD analysis revealed the 3D structure of 1, which exhibits tridentate, vicinal N,N,O-coordination of two symmetry-related Hbdmpza ligands in an elongated octahedral arrangement with four equatorial nitrogen atoms and two axial oxygen atoms. The neutral carboxylic moiety acts as a hydrogen-bond donor to a HSO(4)(-) counterion. The two hydrogensulfates form a unique hydrogen-bonded pair (HSO(4)(-))(2) with very short O center dot center dot center dot O distances (2.59 angstrom) bridged between adjacent [Cu(HL)(2)](2+) coordination units. Also a short O center dot center dot center dot O contact (2.54 angstrom) is present between the C-OH and an 0 of a hydrogensulfate. A characteristic IR C=O vibration is observed at 1700 cm(-1) for 1 and 2, whereas the v(as)(O(2)C) vibration is present at 1650 cm(-1) for 3 and 4. These IR data strongly suggest the presence of Hbdmpza ligands in 1 and 2 and the deprotonated form bdmpza- in 3 and 4. A mononuclear coordination unit [CuL(2)], as proven for 1 by X-ray diffraction, is also proposed for the other compounds 2-4. In compound 4, an additional dinuclear [Cu(2)(O(2)CCH(3))(4)] neutral coordination unit is present, as deduced from the vibration bands v(as)(O(2)C) at 1600 cm(-1) and v(s)(O(2)C) at 1420 cm(-1), which are typical of a carboxylate function, and from the two-species analysis of the chi(M)T(T) curve of the magnetic susceptibility data (2J = -322 cm(-1)). Also, the EPR spectra recorded at different temperatures agree with this structure.}, language = {en} } @article{KozlevcarKovscaJaglicicetal.2009, author = {Kozlevcar, Bojan and Kovsca, Igor and Jaglicic, Zvonko and Pevec, Andrej and Kitanovski, Nives and Strauch, Peter and Segedin, Primoz}, title = {Strong antiferromagnetism in isolated anionic dicopper(II) methanoato paddle-wheel complex}, issn = {0011-1643}, year = {2009}, language = {en} } @article{KozlevcarKovscaJaglicicetal.2009, author = {Kozlevcar, Bojan and Kovsca, Igor and Jaglicic, Zvonko and Pevec, Andrej and Kitanovski, Nives and Strauch, Peter and {\`e}egedin, Primož}, title = {Strong antiferromagnetism in isolated anionic dicopper(II) methanoato paddle-wheel complex}, issn = {0011-1643}, year = {2009}, abstract = {A new ionic compound (C5H6NO)(2)[CU2(mu-O2CH)(4)(O2CH)(2)], 1 formed of 4-hydroxypyridinium cations and a complex anion was synthesized. The anion is a paddle-wheel dicopper carboxylate complex with four syn,syn-bridging and two axial anionic methanoato ligands. The XRD structure determination of 1 reveals that the molecular structure is stabilized by two H-bonds between the cations and the axial paddle-wheel anions (N-H center dot center dot center dot O 2.755(3), O-H center dot center dot center dot O 2.489(2) angstrom). The compound exhibits a very strong (2J = 500 cm(- 1)) intra-binuclear anti ferromagnetic interaction noticed already at room temperature attributed to the methanoato intra-binuclear bridges. The typical EPR S = 1 spin system signals of the dicopper paddle-wheel complexes at 90 and 450- 700 mT are found in the room temperature spectrum, but they are poorly seen in the 110 K spectrum. These signals are of very low intensity and are accompanied by a dominant signal at 320 mT, all closely related to a very strong anti ferromagnetic interaction present in 1.}, language = {en} } @article{VaskovaKitanovskiJaglicicetal.2014, author = {Vaskova, Zuzana and Kitanovski, Nives and Jaglicic, Zvonko and Strauch, Peter and Ruzickova, Zdenka and Valigura, Dusan and Koman, Marian and Kozlevcar, Bojan and Moncol, Jan}, title = {Synthesis and magneto-structural characterization of copper(II) nitrobenzoate complexes containing nicotinamide or methylnicotinamide ligands}, series = {Polyhedron : the international journal of inorganic and organometallic chemistry}, volume = {81}, journal = {Polyhedron : the international journal of inorganic and organometallic chemistry}, publisher = {Elsevier}, address = {Oxford}, issn = {0277-5387}, doi = {10.1016/j.poly.2014.07.017}, pages = {555 -- 563}, year = {2014}, abstract = {Three new copper(II) 4-nitrobenzoato coordination compounds (4-NO(2)bz(-) = 4-nitrobenzoate anions) with N-methylnicotinamide (mna) [Cu(4-NO(2)bz)(2)(mna)(2)(H2O)] (1), [Cu(4-NO(2)bz)(2)(mu-mna)(H2O)](2) (2) and [Cu(mu-4-NO(2)bz)(2)(mna)](2) (3) were synthesized and characterized. Due to a comparison, additional two related compounds [Cu(3,5-(NO2)(2)bz)(2)(mna)(2)(H2O)] (4) (nia = nicotinamide, 3,5-(NO2)(2)bz(-) = 3,5-dinitrobenzoate anions) and [Cu(mu-2-NO(2)bz)(2)(mna)](2) (5) (2-NO(2)bz(-) = 2-nitrobenzoate anions) were isolated. The mononuclear compounds with mna 1 and nia 4 show CuO2N2O chromophores with the water molecule placed at the apex of the square pyramid. The square-pyramidal coordination sphere CuO3NO in 2 differs to CuO2N2O in 1 and 4. Differently, the water molecule is in 2 at the basal-plane, while two mna molecules serve also as bridges via N-py and 0-amido enabling a dinuclear molecular structure 1, 2 and 4 are paramagnetic though a dinuclear structure is seen in 2, while a clear-cut strong antiferromagnetic (AFM) coupling (2J -300 cm(-1)) is found for the compounds 3 and 5. (C) 2014 Elsevier Ltd. All rights reserved.}, language = {en} }