Thiocyanate Groups Research Articles

Synthesis and Evaluation of the Sensitivity and Vibrational Lifetimes of Thiocyanate and Selenocyanate Infrared Reporters.

Two novel 2'-deoxyadenosine (dA) analogues, Si2-dA-SCN and Si2-dA-SeCN, and two novel phenylalanine (Phe) analogues, Boc-Me-PheCH2SCN and Boc-Me-PheCH2SeCN, have been synthesized and the thiocyanate (SCN) and selenocyanate (SeCN) functional groups evaluated as vibrational reporters. The syntheses of Si2-dA-SCN and Si2-dA-SeCN were accomplished in three steps in 16% and 32% overall yields, respectively, and the syntheses of Boc-Me-PheCH2SCN and Boc-Me-PheCH2SeCN were completed in four steps in 8.9% and 2.3% overall yields, respectively. The SCN and SeCN stretch vibrational modes were shown to be sensitive to the local environment by frequency shifts and full-width half-maximum (fwhm) changes in response to tetrahydrofuran (THF) and THF/water solvent mixtures. The vibrational lifetimes of the Si2-dA-SeCN (237±12 ps) and Boc-Me-PheCH2SeCN (295±31 ps) in THF solution were determined by ultrafast infrared pump-probe spectroscopy to be 1.5 to 3 times longer than those for Si2-dA-SCN (140±6 ps) and Boc-Me-PheCH2SCN (102±4 ps). The longer lifetimes for the SeCN analogues were attributed to the better insulating effects of the heavier selenium atom compared to the sulfur atom. The solvent sensitivity and longer vibrational lifetimes compared to other vibrational reporters suggest that SCN and SeCN vibrational reporters are well suited to studying several dynamic processes including protein and nucleic acid hydration and conformational changes, however stability issues may require post-synthetic modification methods to incorporate these reporters into biomacromolecules.

Nonlinear absorption in ionic liquids with transition metallic atoms in the anion

Nonlinear absorption has been investigated by open aperture Z-scan in ionic liquids obtained by combination of 1-butyl-3-methyl-imidazolium cations with anions containing a transition metal (Co, Zn, Cu or Ni) and thiocyanate groups. The laser source was a Ti:Sapphire oscillator (80-fs pulses, λ=810nm, repetition rate of 80.75MHz). All liquids present quite low heat capacities that favor the development of strong thermal effects. Thermal effects and nonlinear absorption make them potential materials for optical limiting purposes.

Ultrafast Structural Fluctuations of Myoglobin-Bound Thiocyanate and Selenocyanate Ions Measured with Two-Dimensional Infrared Photon Echo Spectroscopy.

Structural dynamics within the distal cavity of myoglobin protein is investigated using 2D-IR and IR pump-probe spectroscopy of the N≡C stretch modes of heme-bound thiocyanate and selenocyanate ions. Although myoglobin-bound thiocyanate group shows a doublet in its IR absorption spectrum, no cross peaks originating from chemical exchange between the two components are observed in the time-resolved 2D IR spectra within the experimental time window. Frequency-frequency correlation functions of the two studied anionic ligands are obtained by means of a few different analysis approaches; these functions were then used to elucidate the differences in structural fluctuation around ligand, ligand-protein interactions, and the degree of structural heterogeneity within the hydrophobic pocket of these myoglobin complexes.

Optimisation of total RNA extraction from bovine oocytes and embryos for gene expression studies and effects of cryoprotectants on total RNA extraction

Gene expression is required for understanding bovine oocytes meiotic maturation as well as the potential of embryonic development. In the present study a standardized reagent protocol for total RNA extraction was designed for bovine oocytes and embryos, which is considered specific and less expensive. For such purpose oocytes (n = 795) recovered from about 80 ovaries were divided in three groups: Group 1 modified Trizol (MTP, n = 355); Group 2 Guanidinium thiocyanate protocol (GNTC, n = 140) and Group 3 Commercial Kit protocol (CKP, n = 60). Oocytes belonging to group 1 (n = 100) and 3 (n = 20) were subjected to vitrification using two cryoprotectants 1,2 propandiol (PROH) or Dimethylsulfoxide (DMSO). The 240 remaining oocytes were divided into 3 groups in which 100 were used, in fresh, for in vitro fertilization, and 140 oocytes were vitrified using PROH (n = 70) and DMSO (n = 70) as cryoprotectants, being then fertilized in vitro after thawing. Embryos were used nine days after fertilization. Gene amplification (SDHA, (GAPDH and DNMT1) was performed in oocytes, and gene quantification (DNMT1) in in vitro produced embryos at the stage of blastocyst (n = 10). Efficiency of the extraction was further compared. The purity of all samples to different protocols ranged from 1.10 to 1.25 for GNTC protocol; from 2.05 to 2.63 for the CKP and from 1.50 to 2.11 for the developed MTP, being the last one nearest to the expected purity levels for RNA samples (1.7 to 2.0). On average, for 30 fresh oocytes, from spectrophotometer readings, total RNA concentration was 127.8 ± 9.3 ng μl(-1) for MTP, against 46.4 ± 9.5 ng μl(-1) from CKP and 476 ± 12.9 ng μl(-1) for GNTC protocol. Using the MTP to evaluate RNA in 30 vitrified/thawed oocytes, resulted in a total RNA concentration of 61.3 ± 3.3 ng μl(-1) and 40.0 μ 12.4 ng μ(-1), respectively for DMSO and PROH. Regarding total RNA concentration and purity, in blastocyst stage, more purity was observed in DMSO as compared to PROH (1.8 vs 1.2) (p < 0.05). Better results were also observed on the MTP for gene amplification when compared with the other protocols. For gene quantification, the proposed protocol quantified DNMT1 gene with PCR efficiency (0.933) after normalization against GAPDH and SDHA. Amplification and quantification of genes proved specificity and efficiency of the MTP over the other protocols.

Aryloxyethyl Thiocyanates Are Potent Growth Inhibitors of Trypanosoma cruzi and Toxoplasma gondii.

As a part of our project aimed at searching for new safe chemotherapeutic agents against parasitic diseases, several compounds structurally related to the antiparasitic agent WC-9 (4-phenoxyphenoxyethyl thiocyanate), which were modified at the terminal phenyl ring, were designed, synthesized, and evaluated as growth inhibitors against Trypanosoma cruzi, the etiological agent of Chagas disease, and Toxoplasma gondii, the parasite responsible of toxoplasmosis. Most of the synthetic analogues exhibited similar antiparasitic activity and were slightly more potent than our lead WC-9. For example, two trifluoromethylated derivatives exhibited ED50 values of 10.0 and 9.2 μM against intracellular T. cruzi, whereas they showed potent action against tachyzoites of T. gondii (ED50 values of 1.6 and 1.9 μM against T. gondii). In addition, analogues of WC-9 in which the terminal aryl group is in the meta position with respect to the alkyl chain bearing the thiocyanate group showed potent inhibitory action against both T. cruzi and T. gondii at the very low micromolar range, which suggests that a para-phenyl substitution pattern is not necessary for biological activity.

Vibrational dynamics of azide-derivatized amino acids studied by nonlinear infrared spectroscopy.

Recently, biomolecules which are labeled by azide or thiocyanate groups in solutions and proteins have been studied to examine microscopic environment around a solute by nonlinear infrared (IR) spectroscopy. In this study, we have performed two-dimensional infrared (2D-IR) spectroscopy to investigate the vibrational frequency fluctuations of two different azide-derivatized amino acids, Ala (N3-Ala) and Pro (N3-Pro), and N3(-) in water. From the 2D-IR experiments, it was found that the frequency-frequency time correlation function (FFTCF) of solute can be modeled by a delta function plus an exponential function and constant. FFTCF for each probe molecule has a decay component of about 1 ps, and this result suggests that the stretching mode of the covalently bonded azide group is sensitive to the fluctuations of hydrogen bond network system, as found in previous studies of N3(-) in water. In contrast to FFTCF of N3(-), FFTCF of the azide-derivatized amino acids contains static component. This static component may reflect dynamics of water affected by the solutes or the structural fluctuations of the solute itself. We also performed the IR pump-probe measurements for the probe molecules in water in order to investigate vibrational energy relaxation (VER) and reorientational relaxation. It was revealed that the charge fluctuations in the azide group are significant for the VER of this mode in water, reflecting that the VER rate of N3(-) is faster than those of the azide-derivatized amino acids. While the behaviors of the anisotropy decay of N3-Ala and N3(-) are similar to each other, the anisotropy decay of N3-Pro contains much slower decaying component. By considering the structural difference around the vibrational probe between N3-Ala and N3-Pro, it is suggested that the structural freedom of the probe molecules can affect the reorientational processes.

Ferromagnetic Coupling Through the End-to-End Thiocyanate Bridge in Cobalt(II) and Nickel(II) Chains

The preparation, spectroscopic characterization, and X-ray crystal structure of two novel one-dimensional compounds of formula [MII(tppz)(NCS)(μ-1,3-NCS)]n [tppz = 2,3,5,6-tetrakis(2-pyridyl)pyrazine and M = Co(1) and Ni (2)] are reported. 1 and 2 are isomorphous compounds, and they crystallize in the P21/n space group. Their structures are made up of zigzag chains of cobalt(II) (1) and nickel(II) ions (2) bridged by single end-to-end thiocyanate groups with a tridentate tppz molecule and a terminally bound thiocyanate-N ligand achieving distorted MN5S octahedral surroundings around each metal center. The main source of the distortion of the ideal octahedron is due to the geometrical constraints issued from the occurrence of two fused five-member chelate rings of the tridentate tppz ligand, the values of the N–M–N bond angles covering the range 75.58(9)–78.66(9)°. The M–N bond lengths vary in the range 2.025(3)–2.116(29 (1) and 2.001(2)–2.079(2) Å (2), and they are shorter than the M–S bond distance [2.6395(10) (1) and 2.5225(9) Å (2)]. The values of the intrachain metal–metal separation are 6.4197(7) (1) and 6.3257(5) Å (2). The magnetic properties of 1 and 2 have been investigated in the temperature range 1.9–300 K. Both compounds exhibit intrachain ferromagnetic interactions with values of the magnetic coupling (J) of +4.60 (1) and +7.82 cm–1 (2) [the spin Hamiltonian being defined as Ĥ = −JΣi = 1n–1ŜiŜi+1].

Crystal structure of bis-(thio-cyanato-κS)bis-(thio-urea-κS)mercury(II).

In the title complex, [Hg(NCS)2(CH4N2S)2], the HgII atom is four-coordinated having an irregular four-coordinate geometry composed of four thione S atoms of two thio­cyanate groups and two thio­urea groups. The S—Hg—S angles are 172.02 (9)° for the trans-thio­cyanate S atoms and 90.14 (5)° for the cis-thio­urea S atoms. The mol­ecular structure is stabilized by an intra­molecular N—H⋯S hydrogen bond, which forms an S(6) ring motif. In the crystal, mol­ecules are linked by a number of N—H⋯N and N—H⋯S hydrogen bonds, forming a three-dimensional framework. The first report of the crystal structure of this compound appeared in 1966 [Korczynski (1966 ▸). Rocz. Chem. 40, 547–569] with an extremely high R factor of 17.2%, and no mention of how the data were collected.

Complexes of Copper(I) Thiocyanate with Monodentate Phosphine and Pyridine Ligands and the P(,N)‐Donor Diphenyl(2‐pyridyl)phosphine

AbstractCopper(I) thiocyanate derivatives were prepared by the reaction of CuNCS with pyridine (py) and tertiary monophosphine ligands [PR3 in general; in detail: PPh3, triphenylphosphine, P(4‐FPh)3, tris(4‐fluorophenyl)phosphine)], as well as the potentially bidentate ligand diphenyl(2‐pyridyl)phosphine (PPh2py). Mechanochemical methods were used in some cases to investigate stoichieometries that were not easily accessible by conventional solution syntheses. Three forms of the resulting adducts of CuNCS/PR3/py‐base (1:3–n:n) stoichiometry―all containing four‐coordinate copper(I) atoms and monodentate N‐thiocyanate groups―were confirmed crystallographically. Mononuclear arrays are defined for [(PPh2py)3–n(py)nCuNCS], n = 0, 1, 2, the monodentate thiocyanate being N‐coordinated in all; two polymorphs are observed for the n = 2 complex, both crystallizing in monoclinic P21 (Z = 2) cells with similar cell dimensions, but with aromatic components eclipsed about the Cu–P bond in the PPh3 complex, and staggered in the PPh2py complex. Bridging thiocyanate groups are found in the 1:1:1 CuNCS/PPh2py/2‐methylpyridine (mpy) and P(4‐FPh)3/mpy complexes, wherein centrosymmetric dimers with eight‐membered central rings are obtained: [(R3P)(mpy)Cu(NCS)2Cu(PR3)(mpy)], as is also the case in the parent 1:2 CuNCS/PPh2py adduct [(pyPh2P)2Cu(NCS)2Cu(PPh2py)2]. For the 1:1:1 CuNCS/P(4‐FPh)3/py and PPh3/Brmpy (Brmpy = 3‐bromo‐4‐methylpyridine) adducts, and, likely, CuNCS/PPh2py/py (1:1:1), single‐stranded polymers of the form [···Cu(NCS)(PR3)(py‐base)(Cu)···](∞|∞) with linearly bridging NCS ligands were obtained. Some derivatives, representative of all forms, display medium to strong green to blue luminescence when excited with radiation at 365 nm. The 31P CPMAS NMR spectroscopic data clearly differentiate the inequivalent phosphorus positions within each system, showing a wide range of 1J(31P,63/65Cu) values ranging from 965 Hz for [Cu(NCS)(PPh2py)3] to 1540 Hz for dimeric [(4‐FPh)3P(mpy)Cu(NCS)2Cu(P(4‐FPh)3)(mpy)], reflecting the large variations in the Cu–P bond length.

Syntheses, characterization, and electrochemistry of compounds containing 1-diphenylphosphino-1′-(di-tert-butylphosphino)ferrocene (dppdtbpf)

The reaction of copper(I) salts CuX (X = Cl, Br, I, CN, SCN), [Cu(CH3CN)4]PF6 with 1-diphenylphosphino-1′-di-tert-butylphosphinoferrocene (dppdtbpf) in 1:1 M ratio in DCM–MeOH (50:50 V/V) at room temperature afforded mono and binuclear compounds having formula [Cu2(μ-Cl)2(κ2-P,P-dppdtbpf)2] (1), [Cu2(μ-Br)2(κ2-P,P-dppdtbpf)2] (2) [Cu2(μ-I)2(κ2-P,P-dppdtbpf)2] (3), [Cu2(μ-CN)2(κ2-P,P-dppdtbpf)2] (4), [Cu2(μ2-SCN)2(κ2-P,P-dppdtbpf)2] (5), and [Cu(κ2-P,P-dppdtbpf)(CH3CN)2]PF6 (6). Reacting palladium(II) complex [Pd(C6H5CN)2Cl2] with dppdtbpf gave mononuclear compound [Pd(κ2-P,P-dppdtbpf)Cl2] (7). The reaction of dppdtbpf with sulfur powder under reflux in chloroform afforded a ferrocene diphosphine disulfide dppSdtbpSf (8). All of the synthesized compounds were characterized by elemental analyses, IR, 1H and 31P NMR, ESI-MS and electronic absorption spectroscopy. Molecular structures for the compounds 5, 6, 7 and 8 were determined crystallographically. Compound 5 exists as centrosymmetric dimer in which the two copper atoms are bonded to two dppdtbpf ligands and two bridging thiocyanate groups in μ2-manner. In cationic compound 6, the copper atom is coordinated to one dppdtbpf ligand in κ2-manner and two acetonitrile molecules, whereas in 7, the palladium(II) adopted cis square-planar geometry by coordinating to one dppdtbpf ligand in κ2-manner and two chlorine atoms. Compound 8 revealed a sandwiched structure with both phosphine groups sulfurized. The electrochemical properties of 1–6 were studied by cyclic voltammetry. Compounds 1–6 exhibited moderately weak to strong luminescence properties, however compounds 7 and 8 are non-emissive in the solution state.

Effect of maternal nicotine/thiocyanate exposure during gestational period upon pituitary, thyroid and parathyroid function/morphology of 1-month-old rat offspring

Impact of in utero exposure to nicotine, on the structure of the thyroid-pituitary axis and the parathyroid glands have been examined in 1-month-old rats and compared with that of thiocyanate. Three pregnant female groups were used; control, nicotine and thiocyanate. Treatment started from gestation day (4-20) and the specimens were harvested from the male offspring of all groups at the age of 1 month and processed for light, electronmicroscopic and immunohistochemical examination. Total triiodothyronine (tT3), total thyroxine (tT4) and total thyrotropin (TSH) were quantitatively determined in serum. Both nicotine and thiocyanate activated the thyroid follicular cells, with an increase in height (about 30 %) and a negative feedback on the pituitary thyrotrophs which revealed a reduction in the number of cytoplasmic secretory granules, particularly the thiocyanate group. However, in thiocyanate group there was signs of impaired secretory activity of the thyroid gland. The arbitrary area of parathyroid chief cells, increased (about 45 %) particularly in nicotine group, with signs of reduced activity and a positive feedback on the parafollicular cells which revealed hypertrophy, proliferation (25 %) and increased intensity of positive immunohistochemical reaction for calcitonin. Nicotine impaired chief parathyroid cells activity and consequently activated parafollicular cells. Thiocyanate reduced pituitary thyrotrophs activity, whereas both nicotine and thiocyanate increased thyroid follicular cells activity. This impact of in utero exposure persisted for 1-month postnatal.

A trimethylsulfonium salt with a novel polymeric cadmate anion

The title salt, catena-poly[trimethylsulfonium [μ2-chlorido-di-μ2-thiocyanato-cadmate(II)]] {(C3H9S)[CdCl(NCS)2]}n, consists of trimethylsulfonium cations sandwiched between layers of a two-dimensional polyanion. The Cd(II) centre displays a distorted octahedral environment coordinated by two bridging Cl atoms, two thiocyanate N atoms and two thiocyanate S atoms. The thiocyanate groups adopt the μ-1,3-coordination mode and bridge the Cd(II) centres into a one-dimensional zigzag chain extended along the [110] direction. The Cd(II) centres of the zigzag chains are crosslinked by bridging Cl atoms, forming a two-dimensional polyanion. The two-dimensional anions are linked to layers of trimethylsulfonium cations by weak intermolecular C-H···Cl hydrogen bonds, forming the three-dimensional structure.

Electronic and interfacial behavior of gemini metallosurfactants with copper(ii)/pseudohalide cascade cores

In this paper we discuss the newly synthesized binuclear species [Cu2(L(PY18))2(μ1,1-N3)2(N3)2] (1) and [Cu2(L(PY18))2(μ1,3-SCN)2(NCS)2] (2), as obtained from the monometallic precursor [Cu(L(PY18))Br2]. These gemini metallosurfactants incorporate metal/anion cascade cores and are investigated by experimental and theoretical methods. Diagnostic IR stretches support the presence of μ1,1-bridged (end-on, 2075 cm(-1)) azide groups in 1 and μ1,3-bridged (end-to-end, 2117 cm(-1)) thiocyanate groups in 2. Anion-to-copper LMCT electronic processes at 390 and 440 nm for 1 and at 415 nm for 2 reinforce the nature of the metal/anion cascade cores. Both species are redox-active, magnetically uncoupled due to poor orbital overlap, and robust in the presence of strongly coordinating solvents. At the air-water interface, 1 and 2 yield Langmuir films with high collapse pressures of ca. 60 mN m(-1). Domain formation is considerably less extensive than that observed for the related monometallic precursor and the average molecular areas are in good agreement with their modeled molecular size. The resulting Langmuir-Blodgett films are isolated on silica substrates and investigated using IR-reflectance/absorbance spectroscopy.

Electrochemical and Monte Carlo studies of self-assembled trans-[Fe(cyclam)(NCS)2]+ complex ion on gold surface as electrochemical sensor for nitric oxide

Modification of gold electrode by self-assembled trans-[Fe(cyclam)(NCS)2]+ complex ion to produce an electrochemical sensor for nitric oxide detection was investigated. Dopamine, serotonin and nitrite were examined as interferents. The synthesized complex was characterized by X-ray diffraction and by infrared spectroscopy. The modified electrode was characterized by cyclic voltammetry and by surface enhanced Raman spectroscopy, analytical curves were obtained by square wave voltammetry and Monte Carlo calculations were made to model the interaction of NO molecules with the unmodified and modified surfaces. The complex has distorted octahedron geometry with the thiocyanate groups bonded to the iron ion by the nitrogen atom and in the trans orientation. SERS spectrum and Monte Carlo calculations supported that the complex ion is adsorbed on Au surface from the Au-S bond. The electrochemical current for NO oxidation on the modified electrode was higher than that presented by the bare Au electrode and a good correlation was presented by the experimental analytical curve and the calculated Monte Carlo interaction energy versus amount NO molecules plot. The Monte Carlo calculations indicated that the higher current response for NO oxidation on the Au/trans-[Fe(cyclam)(NCS)2]+ surface was due to the stronger interaction of the NO molecules with complex adsorbed on the Au surface than the interaction of NO with the bare Au surface. The theoretical analyses also revealed that NO molecules cluster on Au surface. Dopamine, serotonin and nitrite were interferents for the detection of NO with dopamine and serotonin was less significant interferents than the nitrite. The proposed modified electrode presented good electrochemical stability, detection limit and quantification limit of 5.15×10−8molL−1 and 1.72×10−7, respectively, which were about one order of magnitude lesser than the corresponding values obtained for the bare Au electrode. The results indicated that the proposed electrode has potential to be applied as a sensor for NO detection.

Formation of polynuclear copper(II)–sodium(I) heterometallic complexes derived from salen-type Schiff bases

Three heteronuclear Cu(II)/Na(I) complexes, [Cu2(salen)2Na(ClO4)(CH3CN)] (1) [Cu2(vanen)2Na2(μ1,1-NCS)2] (2) and [(Cu)2(L)2(Na)2(μ1,1-CH3CN)(H2O)(ClO4)]ClO4 (3), where H2salen=N,N′-ethylenebis-(salicylideneimine) and H2vanen=N,N′-(1,2-ethylene)-bis(3-methoxysalicylideneimine), have been prepared and characterized by elemental analyses, IR and UV–Vis spectroscopy and single crystal X-ray diffraction studies. Two Cu(II)–salen units are connected by an Na ion in complex 1. Two Cu(II)–vanen–Na(I) moieties are connected by bridging thiocyanate groups in complex 2. A novel end-on bridging asymmetric acetonitrile is observed in complex 3.

Molecular determinants of inactivation of the resuscitation promoting factor B from Mycobacterium tuberculosis

Inactivation of revival of Mycobacterium tuberculosis from dormancy is one of the main goals of the WHO Global Plan to stop tuberculosis (TB) 2011–2015, given the huge reservoir of latently infected individuals. This process requires a group of secreted proteins, denoted as resuscitation-promoting factors (Rpfs). Of these, RpfB is the sole member indispensable for resuscitation in vivo. The first class of inhibitors of RpfB was identified among 2-nitrophenylthiocyanates. However, their inactivation mechanism is hitherto not known. To gain insight into the inactivation mechanism of one of the most promising RpfB inhibitors, 4-benzoyl-2-nitrophenyl thiocyanate, NPT7, we have performed replica exchange molecular dynamics (REMD) simulations, starting from the crystal structure of RpfB catalytic domain, derived in this study. We validated our results by resuscitation experiments of M. tuberculosis cultures. The atomic resolution crystal structure of RpfB catalytic domain identified the potential of the enzyme catalytic cleft to bind benzene rings. REMD simulations, 48 replicas, identified the key interactions for the binding of NPT7 to RpfB catalytic site. Of these, an important role is played by the thiocyanate group of NPT7. Consistently, we prove that the substitution of this group implies a complete loss of RpfB inactivation. Our results provide valuable information for modifications of NPT7 structure to enhance its binding affinity to RpfB, with the final aim of developing second-generation inhibitors of therapeutic interest in TB eradication strategy.

N- and S-bonded thiocyanate copper(II) complexes of 2,6-bis-(benzimidazolyl)pyridine – Synthesis, spectroscopic characterization, X-ray structure and DFT calculations

The paper presents a combined experimental and computational study for two novel Cu(II) complexes of 2,6-bis(benzimidazolyl)pyridine. The compounds [Cu(bbp)(NCS)(SCN)]·MeOH (1) and [Cu(bbp)(SCN)Cl]·MeOH·H2O (2) have been studied by IR, UV–Vis spectroscopy and single crystal X-ray analysis. The electronic spectra of 1 and 2 were analyzed and bands were assigned through the DFT/TDDFT procedures. Simultaneous existence of N- and S-coordinated thiocyanate groups makes the complex 1 a rare example of [Cu(N–N–N)(SCN)2] structures. The energetically unfavorable S-binding of the thiocyanate group is stabilized by inter-molecular hydrogen bonds between the N atom of the apical SCN− and the N–H proton of L ligand of an adjacent molecule.

Catena-Poly[[[bis(thiourea-κS)cadmium]-di-μ-thiocyanato-κ2N:S;κ2S:N] dihydrate

The title compound, {[Cd(NCS)2(CH4N2S)2]·2H2O}n, forms a one-dimensional chain parallel to the a axis, caused by the presence of the bridging thio­cyanate groups. Two solvent mol­ecules per complex are present in the lattice. The CdII ion is situated on an inversion centre and is coordinated in a distorted octa­hedral fashion by two N and two S atoms from four thio­cyanate ligands and by two S atoms from two thio­urea mol­ecules. Weak O—H⋯S, N—H⋯O and N—H⋯N inter­actions reinforce the structure.

Structural diversity and magnetic properties of thiocyanate copper(II) complexes

Seven novel compounds [Cu(pz)2(SCN)2]n (1), [Cu(ind)2(SCN)2]n.nH2O (2), [Cu(4-apy)(SCN)2]n (3), [Cu(4-cpy)(SCN)2]n (4), [Cu2(μ-SCN)2(SCN)2(2-aepy)2]n (5), [Cu(2-ambzim)(SCN)2]n (6) and [Cu2(μ-SCN)2(SCN)2(pybzim)2] (7) have been synthesized and characterised structurally (by single X-Ray analysis) and spectroscopically. Variable-temperature magnetic susceptibility measurements were performed for the compounds 1, 3, 5, 6 and 7 and their magneto-structural properties were discussed. In structure 1, the weak CuS coordination bonds expand molecules [Cu(pz)2(SCN)2] to the layer extending along crystallographic (100) plane. In 2, 3 and 4, neutral trans-[Cu(ind)2(SCN)2], trans-[Cu(4-apy)2(SCN)2] and cis-[Cu(ambzim)(SCN)2] molecules are linked by end-to-end thiocyanate groups to an infinite one-dimensional chains. The structures 5 and 7 include neutral dinuclear entities. Copper(II) centers of 5 are doubly bridged by linear thiocyanate anions in end-on fashion, whereas the central ions of 7 are linked by SCN− ions in end-to-end coordination mode. The dinuclear [Cu2(μ1,1-SCN)2(SCN)2(2-aepy)2] units are further linked by μ1,3-double end-to-end thiocyanate groups. Simultaneous existence of both EE and EO bridging modes makes the complex 5 a rare example of thiocyanate-bridged copper(II) structures.

Synthesis, spectroscopic characterization, X-ray structure, and DFT calculations of [Cu(tppz)(SCN)2

This article presents a combined experimental and computational study of [Cu(tppz)(SCN)2], where ttpz stands for 2,3,5,6-tetra-(2-pyridyl)pyrazine. The compound has been studied by IR, UV–Vis spectroscopy, and single crystal X-ray analysis. The geometry around copper atom may be described as a distorted square pyramid. The equatorial plane is defined by three nitrogen atoms of tppz and one nitrogen atom of thiocyanate group. The apical site is occupied by nitrogen atom of the second SCN− ion. The electronic spectrum of [Cu(tppz)(SCN)2] was analyzed, and bands were assigned through the DFT/TDDFT procedures.