Coexistence of Spin Canting and Metamagnetism in a One-Dimensional Mn(II) Compound Bridged by Alternating Double End-to-End and Double End-On Azido Ligands and the Analog Co(II) Compound

Two new compounds of general formula [M(N3)2(dmbpy)] in which dmbpy = 5,5′-dimethyl-2,2′-bipyridine, and M = Mn(II) or Co(II), have been solvothermally synthesized and characterized structurally and magnetically. The structures consist of zig-zag polymeric chains with alternating bis-µ(azide-N1)2M and bis-µ(azide-N1,N3)2M units in which the cis-octahedrally based coordination geometry is completed by the N,N’-chelating ligand dmbpy. The molecular structures are basically the same for each metal. The Mn(II) compound has a slightly different packing mode compared to the Co(II) compound, resulting from their different space groups. Interestingly, relatively weak interchain interactions are present in both compounds and this originates from π–π stacking between the dmbpy rings. The magnetic properties of both compounds have been investigated down to 2 K. The measurements indicate that the manganese compound shows spin-canted antiferromagnetic ordering with a Néel temperature of TN = 3.4 K and further, a field-induced magnetic transition of metamagnetism at temperatures below the TN. This finding affords the first example of an 1D Mn(II) compound with alternating double end-on (EO) and double end-to-end (EE) azido-bridged ligands, showing the coexistence of spin canting and metamagnetism. The cobalt compound shows a weak ferromagnetism resulting from a spin-canted antiferromagnetism and long-range magnetic ordering with a critical temperature, TC = 16.2 K

SYNTHESES, STRUCTURES AND PHYSICAL PROPERTIES OF CYANIDE-BRIDGED M(II)−Ni(II) BIMETALLIC COMPLEXES WITH 2-PYRIDINEETHANOL (M(II) = Fe, Co and Ni)

Bu çalışmada [ML2Ni(μ-CN)2(CN)2] (L= 2-piridinetanol (hepH); M = Fe(II), Co(II) veya Ni(II); bundan sonra M-hepH-Ni olarak kısaltılmıştır.) formülü ile verilen siyanür kompleksleri ilk kez elde edilmiştir. Bu komplekslerin yapıları kırmızı-altı ve Raman spektroskopisi, termal ve elementel analiz teknikleri kullanılarak belirlenmiştir. Komplekslerin elektriksel özellikleri dört uç metodu, manyetik özellikleri ise Evans metodu kullanılarak araştırılmıştır. Titreşim işaretlemeleri tüm gözlenen bandlar için elde edilmiş ve spektral özelliklerin komplekslerin yapılarını destekledikleri görülmüştür. Komplekslerin termal davranışları kuru havada 30 - 700 ºC sıcaklık aralığında TG, DTG ve DTA eğrileri kullanılarak incelenmiştir. Termal analiz eğrilerine göre, hepH ligandının ve siyanür grubunun yapılardan uzaklaştıkları görülmüştür. Son bozunma ürünlerinin metal oksitler olduğu bulunmuştur. Manyetik ölçümlerde komplekslerin deneysel ve teorik manyetik moment değerleri karşılaştırılmıştır. Ayrıca, Fe-hepH-Ni, Co-hepH-Ni ve Ni-hepH-Ni komplekslerinin paramanyetik oldukları belirlenmişti

Two dimensional heteronuclear complexes with cyanide and 4-aminomethylpyridine ligands

YESILEL, Okan Zafer/0000-0002-2284-1578WOS: 000340315200044Two new cyano-bridged two-dimensional heteronuclear complexes, [Cd(NH3)(2)(mu-ampy)Ni(mu-CN)(2)(CN)(2)](n) (1) and [Cd(H2O)(2)(mu-amPY)Pt(mu-CN)(2)(CN)(2)](n) (2) (ampy = 4-aminomethylpyridine), were synthesized and characterized by FT-IR and Raman spectroscopic, thermal (TG, DTG and DTA) and elemental analyses and single crystal X-ray diffraction techniques. They crystallize in the triclinic system and P-1 space group. The Ni(II) or Pt(II) ions are four coordinate with four cyanide-carbon atoms in a square planar geometry and the Cd(II) ion exhibits a distorted octahedral coordination by two different N-atoms from two symmetrically equivalent ampy ligands, two ammine or aqua ligands and two bridging cyano groups.The most important features of the complexes are the presence of obvious M center dot center dot center dot pi (M = Ni(II) or Pt(II)) interactions. (C) 2014 Elsevier B.V. All rights reserved.Eskisehir Osmangazi UniversityEskisehir Osmangazi University [201219A202]This work was supported by the Research Fund of Eskisehir Osmangazi University. Project number: 201219A202. Raman spectra were recorded at Anadolu University, Department of Physics. The authors wish to thank Prof. Dr. Mustafa Senyel and Mrs. Tulay Tiras for the Raman measurements

Cyanide-bridged manganese(II) and chloride-bridged copper(II) complexes with 2-pyridineethanol: synthesis, structural characterization and C-H⋯M interactions

<p>[Mn(hepH)₂Ni(μ-CN)₂(CN)₂]_n (<b>1</b>) and [Cu₂(μ-Cl)₂(μ-hep)₂]_n (<b>2</b>) (2-pyridineethanol abbreviated to hepH) have been synthesized and characterized by FT-IR and Raman spectroscopies, elemental analyses, and single-crystal X-ray diffraction. X-ray single-crystal structure analysis reveals that the structures of <b>1</b> and <b>2</b> consist of 1-D infinite chains. The coordination environment of Mn(II) was identified as distorted octahedral, whereas Ni(II) has a square planar geometry in <b>1</b>. Each Cu(II) in <b>2</b> adopts a distorted square pyramidal geometry in which the basal plane is constructed by oxygen and nitrogen atoms from hep and a bridging chloride ligand, respectively, and the apical position is occupied by the other chloride. The 1-D chains in <b>1</b> and <b>2</b> are extended into a 2-D supramolecular network by O−H⋯N and weak C−H⋯Cl hydrogen bonds, respectively. Adjacent 2-D layers are further connected by C−H⋯M interactions resulting in the formation of 3-D supramolecular networks. The most remarkable properties of complexes are the presence of close C–H⋯M interactions with distance values of 2.58 and 2.93 Å between H⋯Ni and H⋯Cu, respectively. The H⋯Ni interaction distance is shorter than the corresponding values of other tetracyanonickelate(II) complexes.</p

Syntheses and characterizations of tetracyanoplatinate(II) complexes with 2-pyridineethanol

<div><p>The cyanide-bridged heteronuclear polymeric complexes, [M(hepH)₂Pt(μ-CN)₂(CN)₂]_n (M = Cu(II) (<b>1</b>), Zn(II) (<b>2</b>) and Cd(II) (<b>3</b>); hepH = 2-pyridineethanol), have been synthesized and characterized by elemental analysis, FT-IR and Raman spectroscopies, thermal analysis, and single-crystal X-ray diffraction techniques. The crystallographic analyses reveal that <b>1</b> and <b>2</b> crystallize in the triclinic system, space group <i>P-1</i>, while <b>3</b> crystallizes in the monoclinic system, space group <i>P2</i>_<i>1</i><i>/n</i>. The structures of <b>1–3</b> consist of 1-D linear chains in which the M(II) and Pt(II) ions are linked by cyanide ligands. Each M(II) center exhibits a distorted octahedral coordination environment with four nitrogens from two cyanides and two hepH ligands. The 1-D chains are further linked by C–H⋯Pt and O–H⋯N hydrogen bonding interactions to construct 3-D supramolecular structures. Thermal stabilities and decomposition products of the complexes were investigated from 30 to 700 °C in air.</p></div