865-38-3Relevant articles and documents
Structural diversity in Cd(NCS)2-3-cyanopyridine coordination compounds: Synthesis, crystal structures and thermal properties
Jochim, Aleksej,Jess, Inke,N?ther, Christian
, p. 163 - 172 (2020)
Five new compounds with the compositions [Cd(NCS)2(3-cyanopyridine)2]n · 3-cyanopyridine (1), [Cd(NCS)2(3-cyanopyridine)2]n · 1/3 3-cyanopyridine (2), [Cd(NCS)2(3-cyanopyridine)2]n (3), {[Cd(NCS)2]2(3-cyanopyridine)3}n (4), and {[Cd(NCS)2]3(3-cyanopyridine)4}n (5) have been obtained by the reaction of Cd(NCS)2 with 3-cyanopyridine in different solvents. While large amounts of compounds 1-4 could be prepared as powders, only a few single crystals of 5 were accidently obtained. Thermoanalytical investigations have shown that 4 could also be obtained by annealing of 1 or 2 and that under slightly different conditions 5 could be obtained as part of a mixture with 4. The crystal structures of all compounds can be divided in two sets of compounds. Compounds 1, 2 and 3 consist of chains in which the Cd cations show three different coordination environments and in which the coligands are only terminally bonded. In the structures of 4 and 5 similar chains are observed, which are connected into layers via some of the 3-cyanopyridine coligands.
Supramolecular Cd(II) complexes with (E)-N, N′-bis(2-pyridyl) iminoisoindoline (2-pyimiso): Synthesis, X-ray structures, hirshfeld surface analyses, and DFT study of [CdX2(2-pyimiso)2] (X = Cl or NCS)
Bitzer, Rodrigo S.,Visentin, Lorenzo C.,Nascimento, Marco A. C.,Filgueiras, Carlos A. L.
, p. 3261 - 3283 (2016)
The paucity of coordination entities bearing (E)-N,N′-bis(heteroaryl)iminoisoindolines has prompted us to investigate coordination modes and supramolecular features of (E)-N,N′-bis(2-pyridyl)iminoisoindoline (2-pyimiso), a versatile iminobis(pyridyl) ligand. In this article we report the synthesis, spectroscopic characterization and crystal structure analysis of two Cd(II): 2-pyimiso (1?:2) bis-adducts, [CdX2(2-pyimiso)2] [X = Cl (1) or NCS (2)]. Our X-ray structural results reveal that 1 exhibits distorted tetrahedral coordination (four-coordinate geometry index τ4 = 0.92), whereas 2 displays six-coordinate Cd(II) and two four-membered chelate rings (bite angles = 52.5°), each comprising one Cd–Npy [2.247(2) ?] bond and one Cd?Nimine [2.809(21) ?] secondary interaction. Remarkably, in 2 each 2-pyimiso unit binds to Cd(II) according to an unusual bidentate coordination. The contributions of the Cd–N and Cd–Cl bond valences to the total metal valence for both 1 and 2 have been evaluated to confirm the coordination modes of 2-pyimiso, which can be interpreted in terms of J?rgensen’s principle of symbiosis. X-ray structure and Hirshfeld surface analyses have shown that the crystal structure of 1 is determined by two perpendicular 1-D chains formed by weak hydrogen bonds along the a- and c-axes, whereas the supramolecular architecture of 2 exhibits 2-D sheets parallel to the ab-plane interconnected by C–H?πinteractions along the c-axis. A vibrational analysis of both products has been conducted at the DFT B3LYP-D3/LACV3P** level of calculation.
Calorimetric and Raman Spectroscopic Studies of Cadmium(II) Thiocyanato Complexes in N,N-Dimethylformamide
Ishiguro, Shin-ichi,Takamuku, Toshiyuki,Ohtaki, Hitoshi
, p. 3901 - 3906 (1988)
Formation of thiocyanato complexes of cadmium(II) ion has been calorimetrically studied in N,N-dimethylformamide (DMF) at 25 deg C.Calorimetric data obtained were well explained in terms of the formation of a series of four mononuclear n>(2-n)+ (n=1-4, X=SCN) complexes, and their formation constants, enthalpies, and entropies were determined.Raman band shifts for the C-S stretching vibration of SCN- ion indicated that SCN- ion binds to cadmium(II) ion only with the N end within the mono- or dithiocyanato complex, + or .Within the tri- and tetracyanato complexes, thiocyanate ions bind with both the N and S ends, and the coordination modes, - and 2-, were suggested.The coordination modes for the di- and tetrathiocyanato complexes in DMF, and 2-, are different from those in water, and >Cd(NCS)2(SCN)>2-.It is thus shown that the N-bonding becomes more favorable in DMF than in water.Such a result may mainly be ascribed to relatively weakened solvation of the SCN- ion in DMF, especially at the N atom site which is hydrogen-bonded with water molecules but not with DMF.
catena-poly[[bis(thiocyanato-κN)-cadmium(II)]-di-μ-thiourea- κ4S:S]
Wang, Xin Qiang,Yu, Wen Tao,Xu, Dong,Lu, Meng Kai,Yuan, Duo Rong
, p. m336-m337 (2002)
The Cd11 ion in the title complex, [Cd(SCN)2 {SC(NH2)2}2]∞, is situated at a centre of symmetry, and is bound to two N atoms belonging to thiocyanate groups and to four S atoms of bridging thiourea ligands. The structure consists of infinite chains of slightly distorted edge-shared Cd-centred octahedra. The bridging S atoms of two thiourea ligands comprise the common edge. Some thermal properties are described.
New coordination compounds based on Cd(NCS)2(4-ethylpyridine) x (x = 4, 2, 1)
Woehlert, Susanne,Jess, Inke,Naether, Christian
, p. 385 - 391 (2013)
The reactions of different ratios of cadmium(II) thiocyanate and 4-ethylpyridine as neutral co-ligand in water at room temperature leads to the formation of the three new coordination compounds of different topology. In the crystal structure of the 1:4 compound (1:4 = ratio between metal and neutral co-ligand) Cd(NCS)2(4-ethylpyridine)4 (1) discrete complexes are found, in which the cadmium ions are coordinated by two terminal N-bonded anionic ligands and four 4-ethylpyridine co-ligands. In the crystal structure of the 1:2 compound [Cd(NCS)2(4-ethylpyridine) 2]n (2) the cadmium cations are coordinated by two S-bonded, two N-bonded thiocyanato anions and two 4-ethylpyridine ligands, all of them are trans-oriented. The Cd2+ cations are connected by μ-1, 3 bridging thiocyanato anions into chains, which elongate in the direction of the crystallographic a axis. In the crystal structure of the 1:1 compound [Cd(NCS)2(4-ethylpyridine)]n (3) a more condensed coordination network is observed, in which each Cd2+ cation is coordinated by two N-bonded and three S-bonded as well as one 4-ethylpyridine ligand within slightly distorted octahedra. The cadmium cations are linked into chains by μ-1, 3- and μ-1, 1, 3-bridging thiocyanato anions. On heating the 1:4 compound 1 two mass steps are observed in the TG curve, of which the first one is well resolved. The residue obtained after the first TG step is investigated by XRPD, elemental analysis, and IR spectroscopy, it is proven that the 1:2 compound Cd(NCS)2(4-ethylpyridine)2 is obtained as a phase pure material. Based on the results of IR spectroscopic investigations the coordination mode of the thiocyanato anions was additionally investigated. Copyright
Synthesis, structures and magnetic properties of Fe(ii) and Co(ii) thiocyanato coordination compounds: On the importance of the diamagnetic counterparts for structure determination
Woehlert, Susanne,Peters, Lars,Naether, Christian
, p. 10746 - 10758 (2013)
Reaction of Fe(NCS)2 and Co(NCS)2 with 2-methylpyrazine in different molar ratios and solvents at room temperature leads to the formation of five new coordination compounds of composition M(NCS)2(2-methylpyrazine)2(H2O)2 (M = Fe (1-Fe), Co (1-Co)), Co(NCS)2(2-methylpyrazine) 2(CH3OH)2 (2-Co) and Co(NCS) 2(2-methylpyrazine)4·2-methylpyrazine solvate (3-Co). In all of these compounds, discrete complexes are found in which the metal cations are octahedrally coordinated by two terminal N-bonded thiocyanato anions and four N- or O-donor co-ligands. On heating compounds 1-3 in a thermobalance new coordination polymers of composition M(NCS) 2(2-methylpyrazine)2 (M = Co (4-Co), Fe (4-Fe)) are obtained in the first step, which transform into M(NCS)2(2- methylpyrazine) (M = Co (5-Co), Fe (5-Fe)) in the second. Because of the low chalcophilicity of these cations, compounds 4 and 5 are not accessible from solution. Further investigations prove that 4-Co and 4-Fe obtained by thermal decomposition are of low crystallinity, might be isotypic and might consist of metal cations, in which the anionic ligands are only terminal N-bonded. In contrast, 5-Co and 5-Fe are of good crystallinity but their structure cannot be solved from X-ray powder data. However, a compound of the same composition (5-Cd) based on the more chalcophilic cadmium can easily be crystallized from solution and characterized by single crystal X-ray diffraction. This compound is isotypic to 5-Co and 5-Fe and therefore their structures were determined by Rietveld refinements. In their crystal structures the metal atoms are linked by μ-1,3-bridging thiocyanato anions into a 2D network. Magnetic measurements reveal that compounds 1-4 show only Curie-Weiss paramagnetism and that for 5-Fe antiferromagnetic ordering is observed. In contrast, 5-Co shows metamagnetic behavior with a very large critical field. Finally, it was shown that 4-Co and 4-Fe are hygroscopic and transform within minutes into the hydrates 1-Co and 1-Fe. The Royal Society of Chemistry 2013.
Syntheses, structures, and thermal reactivity of new ZnII and CdII thio- and selenocyanato coordination compounds
Boeckmann, Jan,Reinert, Thorben,Jess, Inke,Naether, Christian
, p. 1137 - 1144 (2011)
Reaction of ZnII and CdII thiocyanate or selenocyanate with pyrazine leads to the formation of new ZnII and CdII coordination compounds. The structures of [Zn(NCSe) 2(pyrazine)2]n (1A), [Cd(NCS) 2(pyrazine)2]n (2A) and [Cd(NCSe) 2(pyrazine)2]n (3A) consist of octahedrally coordinated metal cations which are surrounded by two terminal N-bonded anions and two μ2-bridging pyrazine molecules. The metal cations are connected via the pyrazine ligands into layers, which are further linked by weak intermolecular S...S respectively Se...Se interactions. Investigations on the thermal degradation behavior of 1A, 2A, and 3A using simultaneous differential thermoanalysis and thermogravimetry as well as X-ray powder diffraction, IR- and Raman spectroscopy prove that on heating, the pyrazine-rich compound 1A decomposes in one step into zinc selenocyanate without the formation of a pyrazine-deficient intermediate. In contrast, for compounds 2A and 3A a stepwise decomposition is observed, leading to the formation of the pyrazine-deficient compounds [Cd(NCS)2(pyrazine)]n (2B-I and 2B-II) and [Cd(NCSe)2(pyrazine)]n (3B) as intermediates. The structures and the thermal reactivity are discussed and compared with that of related transition metal thiocyanates and selenocyanates with pyridine as N-donor ligand. Copyright
New cadmium thio- and selenocyanato coordination compounds: Structural snapshots on the reaction pathway to more condensed anionic networks
Jess, Inke,Boeckmann, Jan,Naether, Christian
, p. 228 - 236 (2012)
In this contribution several new coordination compounds on the basis of cadmium(ii) thio- and selenocyanate with pyrimidine as co-ligand were prepared and investigated for their structural, thermal and spectroscopic properties. The reaction of cadmium(ii) thiocyanate with pyrimidine leads to the formation of four compounds, which from a structural point of view are closely related. In the most pyrimidine-rich 1:2 compound [Cd(NCS)2(pyrimidine) 2]n (1A) (1:2 = ratio between metal salt and the co-ligand pyrimidine) the Cd cations are linked by the pyrimidine ligands into layers and are additionally coordinated by two terminal N-bonded anions. In the 2:3 compound {[Cd(NCS)2]2(pyrimidine)3}n (1B) the Cd cations are linked into chains by μ-1,3 bridging thiocyanato anions, which are connected into layers by only half of the pyrimidine ligands, whereas the other co-ligands are only terminal coordinated. Further reduction of the pyrimidine content leads to the formation of the 1:1 2D compound [Cd(NCS)2(pyrimidine)]n (1CI) in which the terminal N-bonded thiocyanato anions become bridging. Surprisingly, crystallization experiments lead to the formation of an additional pyrimidine-deficient intermediate of composition {[Cd(NCS)2]3(pyrimidine) 2}n (1D), in which some of the μ-1,3 coordinated anions transform into μ-1,1,3 bridging thiocyanato anions. Consequently the four structures can be used as snapshots of intermediates on the way to a more condensed thiocyanato coordination network. In contrast, with cadmium selenocyanate only two different compounds were obtained. The 1:2 compound [Cd(NCSe)2(pyrimidine)2]n (2A) is not isotypic to 1A and shows a completely different coordination topology whereas the pyrimidine-deficient 1:1 compound (2B) shows a more condensed network with μ-1,3 coordinating selenocyanato anions. On heating, the 1:2 compound 1A decomposes into Cd(NCS)2via a new polymorphic modification (1CII) as intermediate which is metastable, whereas the 1:2 selenocyanato compound 2A transforms into the 1:1 compound 2B on heating which cannot be obtained phase pure under these conditions. If faster heating rates are used, there are indications for the formation of a 3:2 compound, which is amorphous to X-rays. The results are compared with those obtained for related thio- and selenocyanato coordination polymers with pyridine, pyridazine and pyrazine as co-ligand. Moreover, their impact on the structures and thermal reactivity of analogous paramagnetic compounds is discussed in detail. Based on the structural data of compound 1D the unknown structures of two intermediates were determined, which are formed in the thermal decomposition reaction of the Mn and Fe thiocyanato pyrimidine coordination polymers, reported recently. The Royal Society of Chemistry.
Cesium-133 NMR study of CsCd(SCN)3: Relative orientation of the chemical shift and electric field gradient tensors
Kroeker, Scott,Eichele, Klaus,Wasylishen, Roderick E.,Britten, James F.
, p. 3727 - 3733 (1997)
Single-crystal NMR was used to characterize the cesium-133 chemical shift and electric field gradient (EFG) tensors in CsCd(SCN)3. The principal axes of the two interaction tensors are not coincident, a reflection of the general positioning of cesium nuclei within the unit cell. Relative orientations of the chemical shift and EFG tensors have been determined, but assignment of the two magnetically distinct sites remains elusive. The span of the chemical shift, 94.4 ppm, is moderate in comparison with other cesium salts, and the magnitude of the nuclear quadrupole coupling constant, 148 kHz, is in the midrange of those reported for cesium compounds. Excellent agreement is observed between experimental 133Cs NMR spectra of a stationary powder sample and spectra calculated using NMR parameters from the single-crystal analysis. Moreover, simulations indicate that the static line shape is very sensitive to the relative orientation of the chemical shift and EFG tensors. Experimental 133Cs NMR spectra obtained with magic-angle and variable-angle spinning are well reproduced by calculations utilizing single-crystal NMR data.
New Cd thio- and selenocyanato coordination compounds and their impact on the structures and reactivity of their paramagnetic counterparts
Boeckmann, Jan,Jess, Inke,Reinert, Thorben,Naether, Christian
, p. 5502 - 5511 (2011)
Treatment of cadmium(II) thio- and selenocyanate with pyridazine leads to the formation of new cadmium(II)thiocyanato and selenocyanato coordination compounds [Cd(NCS)2(pyridazine)4] (1A), [Cd(NCSe) 2(pyridazine)3]n (2A), [Cd(NCS) 2(pyridazine)2]n (1B), [Cd(NCSe) 2(pyridazine)2]n (2B) and [Cd(NCS) 2(pyridazine)]n (1C) which were characterised by single-crystal X-ray diffraction. Investigations of the thermal degradation behaviour of 1A and 2A using simultaneous differential thermoanalysis and thermogravimetry as well as X-ray powder diffraction, IR- and Raman spectroscopy prove that on heating, the pyridazine-rich compounds 1A and 2A decompose in a stepwise manner leading in the first TG step to the formation of the pyridazine-deficient compounds [Cd(NCS)2(pyridazine) 2]n (1B) and [Cd(NCSe)2(pyridazine) 2]n (2B) as intermediates. While the selenocyanato compound decomposes on further heating, for the thiocyanato compound an additional TG step is observed, in which a pyridazine-deficient 1:1 compound of composition [Cd(NCS)2(pyridazine)]n (1C) is formed. The structures and thermal reactivity are discussed and compared with that of related transition metal thiocyanato and selenocyanato coordination compounds with pyridine and pyrazine as the coligand. More importantly, on the basis of these investigations, the hitherto unknown structures of the ligand-deficient paramagnetic counterparts were determined. The crystal structures and thermal degradation behaviour of new CdII thiocyanato and selenocyanato coordination compounds are reported. The latter act as structural models for their paramagnetic counterparts. Copyright
