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1.
A. Fratiello V. Kubo-Anderson E. Bolanos R. D. Perrigan L. Saenz S. M. Stoll 《Journal of solution chemistry》1996,25(11):1071-1082
A direct, low-temperature hydrogen-1, carbon-13, and nitrogen-15 nuclear magnetic resonance study of lutetium(III)-isothiocyanate complex formation in aqueous solvent mixtures has been completed. At –100°C to –120°C in water-acetone-Freon mixtures, ligand exchange is slowed sufficiently to permit the observation of separate1H,13C, and15N NMR signals for coordinated and free water and isothiocyanate ions. In the13C and15N spectra of NCS–, resonance signals for five complexes are observed over the range of concentrations studied. The13C chemical shifts of complexed NCS– varied from –0.5 ppm to –3 ppm from that of free anion. For the same complexes, the15N chemical shifts from free anion were about –11 ppm to –15 ppm. The magnitude and sign of the15N chemical shifts identified the nitrogen atom as the binding site in NCS–. The concentration dependence of the13C and15N signal areas, and estimates of the fraction of anion bound at each NCS–:Lu3+ mole ratio, were consistent with the formation of [(H2O)5Lu(NCS)]2+ through [(H2O)Lu(NCS)5]2–. Although proton and/or ligand exchange and the resulting bulk-coordinated signal overlap prevented accurate hydration number measurements, a good qualitative correlation of the water1H NMR spectral results with those of13C and15N was possible. 相似文献
2.
A. Fratiello V. Kubo-Anderson E. Bolanos J. V. Ortega R. D. Perrigan L. Saenz S. M. Stoll K. Wong 《Journal of solution chemistry》1997,26(2):163-181
A continuation of the contact ion-pairing studies of the trivalent lanthanides by direct, low-temperature, multinuclear magnetic
resonance techniques has been completed for the europium(III)-isothiocyanate system. In water-acetone-Freon-22 solvent mixtures,
ligand exchange is sufficiently slow at — 100°C to - 125°C to permit the observation of13C and15N NMR signals for Eu3+-NCS- contact ion-pair complexes. With each nuclide, signals for four complexes are observed, displaced approximately 250 ppm upfield
from free anion in the13C spectra, and 2,500 ppm upfield from bulk NCS- in the15N spectra. The concentration dependence of the signal areas is consistent with the formation of Eu(NCS)2+ through Eu(NCS)
4
1-
, with water molecules completing the solvation shell. In the15N NMR spectra, the large chemical shifts identified the nitrogen atom as the NCS- binding site. Also, the observation of two15N NMR signals for isomers of Eu(NCS)
2
1+
was possible in several spectra. In methanol, a medium of higher dielectric constant, complex formation was diminished, with
signal area integrations confirming the dominance of Eu(NCS)
1
2+
. A comparative binding study of Cl- and NCS- also was made by35C1 NMR chemical shift and linewidth measurements in water-methanol mixtures. The much stronger coordinating ability of NCS- was evident in these experiments, but there is a strong possibility of Eu3+-Cl- ion-pairing in the absence of this anion. 相似文献
3.
A. Fratiello V. Kubo-Anderson D. Lee R. Perrigan K. Wong 《Journal of solution chemistry》1998,27(7):581-600
Multinuclear magnetic resonance studies of trivalent lanthanide inner-shell ion-pairing with nitrate and isothiocyanate are continuing. For NCS– solutions in water–acetone–Freon mixtures at low temperature, generally –100 to –125°C, ligand exchange is slow enough to permit the observation of 13C and 15N NMR signals for coordinated and free anions. For samariuni(III) solutions, four coordinated NCS–signals, displaced about +35 ppm and +250 ppm from free anion, are observed in the 13C and 15N NMR spectra, respectively. The 13C and 15N NMR data are complementary, showing a signal area concentration dependence and measured coordination numbers consistent with the formation of Sm(NCS)2+ through Sm(NCS)
4
1
. The coordination numbers reach a maximum of about three moles of NCS– per mole of Sm(III) with both nuclides, a result confirmed by spectral appearance showing the dominance of Sm(NCS)3 at the highest concentration studied. An analysis of the chemical shifts indicates that binding occurs at the nitrogen atom of NCS–. In water–methanol, due to the higher dielectric constant of such mixtures, coordination was less extensive. A competitive binding study with Ci– by 35Ci NMR demonstrated conclusively the superior coordinating ability of NCS–. 相似文献
4.
Ahmed Y. Ali-Mohamed 《Transition Metal Chemistry》1991,16(1):14-17
Summary The activities of the diethylenetriaminemonoacetatocobalt(III) complexes, [Co(en)(DTMA)]I2, [CoX2(DTMA)] and [CoCO3(DTMA)]·H2O (DTMA=diethylenetriaminemonoacetato or formally 3-amino-3, 6-diazaoctanato; en=ethylenediamine, X=Cl–, NO
2
–
, NCS–) were studied onEscherichia coli B growing in a minimal glucose medium in both lag- and log-phases. Activities decrease in the order: [Co(NCS)2(DTMA)]> [Co(NO2)2(DTMA)]>[Co(en)(DTMA)]I2>[CoCl2(DTMA)] >[CoCO3(DTMA)]·H2O. The antagonistic activities of the complexes were also studied. 相似文献
5.
《Journal of Coordination Chemistry》2012,65(3):483-490
Mononuclear NCS? containing complexes, [M(NCS)2L] (L?=?N,N-bis(3,5-dimethylpyrazol-1-ylmethyl)aminomethylpyridine), [Cu(NCS)2L′] (L′?=?N-(3,5-dimethylpyrazol-1-ylmethyl)aminomethylpyridine), and NCSe? containing complexes [ML(NCSe)(H2O)]ClO4 (M?=?Ni+2, Co+2) have been synthesized and characterized by elemental analysis, spectroscopic, and physico-chemical methods. Structural studies of [Cu(NCS)2L′] show copper is five coordinate with distorted trigonal bipyramidal geometry with two cis NCS?. [M(NCS)2L] and [ML(NCSe)(H2O)]ClO4 (M?=?Ni+2 and Co+2) are expected to be octahedral. 相似文献
6.
Anthony Fratiello Vicki Kubo-Anderson Rebecca A. Lee Marquis Patrick Richard D. Perrigan Tanya R. Porras Amy K. Sharp Kenneth Wong 《Journal of solution chemistry》2001,30(1):77-97
Multinuclear magnetic resonance spectroscopic studies of the trivalent lanthanide complexes with isothiocyanate have been completed for the praseodymium(III) and neodymium(III) ions. In water–acetone–Freon mixtures, at temperatures low enough to slow ligand exchange, usually –85 to –125°C for isothiocyanate, separate carbon-13 and nitrogen-15 NMR signals can be observed for free anion and NCS- in each metal–ion complex. For both metal ions, 15N NMR signals are observed for four complexes, displaced about +1500 ppm downfield from free NCS- for Pr3+ and about +2000 ppm for Nd3+. In the 13C NMR spectra, only three peaks are observed for the complexes of both metal anions, with signal overlap obscuring the resonance for the fourth complex. However, the metal ion coordination numbers, obtained by integration of the resonance signals, are comparable in the 15N and 13C spectra, approaching a maximum value of about 3. These spectral data indicate the formation of Ln(NCS)2+ through Ln(NCS)
4
1-
occurs for both lanthanides in these solvent systems, a result also observed previously for Ce3+, Sm3+, and Eu3+ in our laboratory. Attempts to study these complexes in water–methanol were unsuccessful, due to the inability to achieve low enough temperatures to slow ligand exchange sufficiently. Results for NCS- and Cl- competitive-binding studies by 35Cl NMR for both metal ions will also be described. 相似文献
7.
Erica Brendler Berthold Thomas Siegfried Schönherr 《Monatshefte für Chemie / Chemical Monthly》1992,123(4):285-289
Using aqueous GaCl3 and chloride containing Ga(ClO4)3 solutions measurements have been carried out to investigate the formation of complexes with mixed ligands beside the [GaCl4]– ion. In contrast to the Raman spectra, which contain only the signals of the [GaCl
4
–
] and the [Ga(H2O)6]3+ ion, the71Ga-NMR spectra give clear evidence for the existence of complexes with mixed ligands. Investigations at low temperatures showed their coordination to be octahedral resulting in species [GaCln(H2O)6–n
](3–n)+. 相似文献
8.
Trávníček Zdeněk Machala Viktor Szüčová Lucie Maloň Michal Marek Jaromír 《Transition Metal Chemistry》2004,29(4):352-357
A series of new [NiX(S2P{O-c-Hex}2)(PPh3)](X = Cl–, Br–, I– and NCS–)(1)–(4) and [Ni(NCS)(S2P{OR}2)(PPh3)][R =n-Pr (5), i-Pr (6)] complexes has been synthesized and characterized by elemental analyses, f.i.r., i.r., u.v.–vis., 1H-, 13C{1H}- and 31P{1H}-n.m.r. spectra, magnetochemical and conductivity measurements. A single crystal X-ray analysis of [Ni(NCS)(S2P{O-n-Pr}2)(PPh3)](5) reveals the molecular structure of the complex and confirms a square-planar geometry around the central atom of nickel with the NCS anion coordinated via the nitrogen atom. 相似文献
9.
Anthony Fratiello Vicki Kubo-Anderson Rebecca Lee Marquis Patrick Richard Perrigan Tanya Porras Shantanu Sharma Stephanie Stoll 《Journal of solution chemistry》2002,31(9):681-702
An 1H, 13C, and 15N NMR study has been completed for the complexes of La(III), Tm(III), and Yb(III) with nitrate and isothiocyanate in aqueous solvent mixtures. Signals for four complexes are observed for both the Tm3+–NO3
– and Yb3+–NO3
– solutions, with the species identified as the mono-, di-, tetra-, and either the penta - or hexanitrato. These results are consistent with those determined for the nitrate complexes of the Ce(III)–Eu(III) metal ions. The chemical shifts for the Tm(III) and Yb(III) nitrate complexes indicate a pseudocontact binding mechanism prevails. The complexes of diamagnetic La(III) with NO3
– produce three signals in the 15NO3
– spectra, with assignments paralleling those observed with the paramagnetic lanthanides. Three complexes are formed in the La3+–NCS– solutions, with signals assigned to the mono-, di-, and triisothiocyanato species. 相似文献
10.
D. V. Soldatov P. A. Trushin V. A. Logvinenko E. V. Grachev 《Journal of Structural Chemistry》1993,34(2):232-238
Three new compounds have been synthesized: [Mg(4-MePy)4(NCS)2]·0.67(4-MePy)·xH2O (x=0.07–0.24 [Mg(4-MePy)4(NCS)2]·(4-MePy) and [MgPy4(NCS)2]·2Py·2H2O. Their structures have been investigated by Raman spectroscopy and the first two compounds have been shown to be isostructural with the clathrates [Cu(4-MePy)4(NCS)2]·0.67(4-MePy)·0.33H2O and [Ni(4-MePy)4(NCS)2]·(4-MePy). Thermal and other properties have been studied. It was concluded from an analysis of the literature that pyridine complexes of Mg and Ca are capable of forming clathrates with Py as guest molecule, although these compounds have not been examined before from the point of view of clathrate chemistry.Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated from Zhurnal Strukturnoi Khimii, Vol. 34, No. 2, pp. 66–73, March–April, 1993. 相似文献
11.
A. Fratiello V. Kubo-Anderson E. Bolanos O. Chavez J. Ortega R. D. Perrigan F. Reyes L. Saenz S. M. Stoll T. Thompson 《Journal of solution chemistry》1996,25(4):345-367
A direct, low-temperature nuclear magnetic resonance spectroscopic study of europium(III)-nitrate contact ion-pairing has been completed, and preliminary results for europium(III)-isothiocyanate have been obtained. In water-acetone-Freon mixtures, at –110°C to –120°C, four15N NMR signals are observed for coordinated nitrate ion. Area evaluations of the signals and their concentration dependence indicate the formation of Eu(NO3)2+, Eu(NO3)
2
1+
, and two higher complexes, possibly the tetra-, with either the penta-or hexanitrato. This correlates well with similar15N NMR results obtained for Ce(III), Pr(III), Nd(III), and Sm(III). As a result of a higher dielectric constant, complex formation is significantly less in water-methanol mixtures, wheein only three complexes form with Eu(NO3)
2
1+
dominating at the highest anion concentrations. Competitive complexing experiments in water-methanol also were made by35Cl NMR chemical shift and linewidth measurements, as well as15N NMR. Initial experiments with the Eu3+-NCS– system show four coordinated anion signals, displaced from the bulk anion peak by about –250 ppm and –2,500 ppm in the13C and15N NMR spectra, respectively. Area evaluations are consistent with the presence of Eu(NCS)2+ through Eu(NCS)
4
1-
in these solutions. A consideration of the chemical shifts identified the nitrogen atom as the site of binding in the NCS–. A discussion of these preliminary results, as well as those for several other metal-ions, will be presented. 相似文献
12.
A. Fratiello V. Kubo-Anderson E. Bolanos O. Chavez F. Laghaei J. V. Ortega R. D. Perrigan F. Reyes 《Journal of solution chemistry》1994,23(9):1019-1047
The extent of inner-shell, contact ion-pairing between samarium(III)-nitrate and in a preliminary manner, samarium(III)-isothiocyanate, has been determined by a direct, low-temperature, multinuclear magnetic resonance technique. In water-acetone mixtures containing Freon-12 or Freon-22, the slow exchange condition is achieved at –110 to –120°C, permitting the observation of15N NMR resonance signals for bulk and coordinated nitrate. In these mixtures, signals are observed for Sm(NO3)2+, Sm(NO3)
2
+
, and two higher complexes, possibly the tetranitrato with either the penta-or hexanitrato.1H NMR signals for bound water molecules in these mixtures were observed, but accurate hydration numbers can not yed be determined. In anhydrous or aqueous methanol mixtures,15N NMR signals for only three complexes are observed, with the dinitrato clearly dominating. Using15N and35Cl NMR chemical shift and linewidth measurements, the superior complexing ability of nitrate compared to perchlorate and chloride, was demonstrated. Successful preliminary13C and15N NMR measurements of Sm3+-NCS– interactions in water-acetone-Freon-22 mixtures also have been made. The13C NMR spectra reveal signals for five complexes, presumably Sm(NCS)2+ through Sm(NCS)
5
2–
. In the15N NMR spectra, signals for only three complexes are observed (the result of insufficient spectral resolution.) displaced about +240 ppm from bulk anion. 相似文献
13.
Yong-Min Lee Bun-Joo Kim Hee-Jin Kim Sang-Yub Kim Sung Kwon Kang Sung-Nak Choi 《Polyhedron》2009,28(14):3060-3064
Tetrahedrally distorted copper(II) sparteine pseudohalide complexes having a CuN4 chromophore were prepared and characterized by various spectroscopic techniques and X-ray crystallography. Among them, the crystal structures of copper(II) isothiocyanate complexes with two sparteine epimers, (−)-l-sparteine (Sp) and (−)-α-isosparteine (α-Sp), were determined. The NSp–Cu–NSp plane in copper(II) (−)-l-sparteine isothiocyanate [Cu(Sp)(NCS)2] and copper(II) (−)-α-isosparteine isothiocyanate [Cu(α-Sp)(NCS)2] is twisted by 58.2(6)° and 52.2(9)°, respectively, from the NNCS–Cu–NNCS plane. Based on the values of the dihedral angles and tilted distances of these two complexes, the geometry around Cu(II) in Cu(α-Sp)(NCS)2 is more distorted from the perfect tetrahedron than that in Cu(Sp)(NCS)2. For copper(II) sparteine pseudohalide (NCS− and N3−) complexes having a CuN4 chromophore, the EPR and the optical spectral data were collected. The results of X-ray crystallography and ESR spectroscopy are in a good agreement with the assumption that the degree of distortion from planarity to tetrahedron will reduce the A|| value of four-coordinate copper(II) sparteine pseudohalide complexes. 相似文献
14.
Robert W. Hay Mahesh P. Pujari Ramesh Bembi Bakir Jeragh Paul R. Norman 《Transition Metal Chemistry》1989,14(5):393-400
Summary The reaction of [CrCl3(DMF)3] with C-meso-5, 12-dimethyl-1, 4, 8, 11-tetra-azacyclotetradecane(LM) in DMF gives a mixture ofcis-[CrLMCl2]Cl (ca. 90%) andtrans-[CrLMCl2]Cl (ca. 10%). These complexes are readily separated, as thecis-isomer is insoluble in warm methanol while thetrans-isomer is soluble. Using the dichlorocomplexes as precursors it has been possible to prepare a range ofcis-[CrLMX2]+ complexes (X=Br–, NO
3
–
, N
3
–
, NCS– and X2=bidentate oxalate) and alsotrans-[CrLMX2]+ complexes (X=Br–, H2O or NCS–). The spectroscopic properties and detailed stereochemistry of the complexes are discussed.The aquation and base hydrolysis kinetics ofcis- andtrans-[CrLMCl2]+ have been studied at 25° C. Base hydrolysis of thecis-complex is extremely rapid with KOH =1.46×105 dm3 mol–1 at 25° C. This unusual reactivity appears to be associated with thetrans II stereochemistry of thesec-NH centres of the macrocycle. Base hydrolysis of thetrans complex with thetrans III chiral nitrogen stereochemistry is quite normal with kOH =1.1 dm3 mol–1 s–1 at 25° C. 相似文献
15.
《Journal of Coordination Chemistry》2012,65(6):942-951
Two new complexes, trans-[MnL2(NCS)2] (1) and trans-[CoL2(H2O)(EtOH)](ClO4)2?·?H2O (2) with asymmetrical triaryltriazole ligands [L?=?3-(p-chlorophenyl)-4-(p-methylphenyl)-5-(2-pyridyl)-1,2,4-triazole], have been synthesized and characterized by elemental analysis, FT-IR, ESI-MS, and single-crystal X-ray diffraction. In the complexes each L adopts a chelating bidentate mode via the nitrogen of pyridyl and triazole. Both complexes have a similar distorted octahedral core with two NCS? ions in the trans position in 1, while one H2O and one EtOH are present in the axial sites in 2. 相似文献
16.
E. Sathiyaraj Samuele Ciattini 《Phosphorus, sulfur, and silicon and the related elements》2016,191(7):1042-1050
Twelve new nickel(II) complexes of functionalized dithiocarabamates [Ni(S2CNRR')2](1-6) and [Ni(S2CNRR')(NCS)(PPh3)](7-12) [where R=furfuryl; R'=2-hydroxy benzyl (1,7), 3-hydroxy benzyl (2,8), 4-hydroxy benzyl (3,9), 4-methoxy benzyl (4,10), 4-fluoro benzyl (5,11), 4-chloro benzyl (6,12)] have been prepared and characterized by elemental analysis, IR, UV-Vis and NMR (1H and 13C) spectroscopy. IR spectra of the complexes support the bidentate coordination of dithiocarbamate ligands. Electronic spectral studies on complexes 1-12 indicate square planar geometry around the nickel(II) central atom. In the 13C NMR spectra, the upfield shift of NCS2 carbon signal for heteroleptic complex (7-12) compared to homoleptic complexes (1-6) is due to the effect of PPh3 on the mesomeric drift of electron density toward nickel through thioureide C-N bond. Single crystal X-ray structural analysis of complex 11 confirms that the coordination geometry about the Ni(II) is distorted square planar. A rare intramolecular anagostic interaction C–H…Ni [Ni???H=2.804 Å] is observed. The packing of complex 11 is stabilized by non-conventional C–H…S, C–H?F and C–H?π(chelate, NiS2C) bonding interactions. 相似文献
17.
Mitra Samiran Dey Dilip Kumar Karan Nirmal Kumar Rosair Georgina 《Transition Metal Chemistry》2002,27(6):613-616
Two stable diamine complexes [Co(1,1-dmen)2(NCS)2]SCN · (H2O)1.5
(1) and [Co(pn)2(NCS)2]SCN · (H2O)1.5
(2) have been synthesised and characterised by elemental analysis, i.r. and electronic spectra and t.g.a. The structure of (1) has been confirmed by single-crystal X-ray diffraction and reveals that the cobalt complex has octahedral geometry and consists of two crystallographically independent cations, both situated on centres of inversion. In the crystal structure of (1), free H2O molecules and SCN– ions form an extensive hydrogen bonding network with the cation. It is an ordered pseudo-polymorph of a previous structure determination. Both (1) and (2) are diamagnetic. 相似文献
18.
Anthony Fratiello Vicki Kubo-Anderson Deborah J. Lee Tai Mao Kwok Ng Scott Nickolaisen Richard D. Perrigan Victor San Lucas Wayne Tikkanen Annie Wong Kenneth Wong 《Journal of solution chemistry》1998,27(4):331-359
A study of zinc(II) and cadmium(II) complexes with isothiocyanate ion has been completed, using a low-temperature, multinuclear magnetic resonance technique that permits the observation of separate resonance signals for bound and free ligand, and Cd(II) metal ion. The Zn2+–NCS– complexes were studied by 1H, 13C, and 15N NMR spectroscopy. In the 1H spectra, the intensity of the coordinated water signal, corresponding to a Zn(II) hydration number of six in the absence of NCS–, decreases dramatically as this anion is added, indicating the complexing process involves more than a simple 1:1 ligand replacement. The 13C and 15N NMR spectra reveal signals for four species, most reasonably assigned to a series of tetrahedrally coordinated Zn2+–NCS– complexes. In the Cd2+–NCS– solution spectra, the 13C and 15N signals for four complexes also are observed and they are three line patterns, corresponding to a doublet from 113Cd J-coupling, and a dominant central peak, resulting from bonding to magnetically inactive Cd isotopes. The 113Cd spectra, showing signals for four complexes, correlate well in all respects with the 13C and 15N results, including coupling in specific cases. The spectral results for both metal ions reflect binding at the nitrogen atom of NCS–, with the complexes changing from an octahedral to a tetrahedral configuration when doing so. Confirming evidence for these conclusions also was provided by several infrared measurements of these metal–ion systems. 相似文献
19.
Ya. Z. Voloshin N. A. Kostromina A. Yu. Nazarenko 《Theoretical and Experimental Chemistry》1990,26(3):352-354
Syntheses are reported for CoD3(BF)2 and [CoD3(BF)2]BF4,where H
2
D is dimethylglyoxime, -benzyldioxime, or cyclohexanedione dioxime. The IR spectra at 400–4000 cm
–1 have been measured, as have the electronic absorption spectra and the1H,13C,and
11BNMR spectra; a comparison is made with the spectra of the analogous iron(II) complexes.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 26, No. 3, pp. 375–377, May–June, 1990. 相似文献
20.
Summary MnIII is stabilized by pyrophosphate in weakly acidic solutions. The nature of the complex formed was elucidated spectrophotometrically. The kinetics of MnIII oxidation of thiocyanate in pyrophosphate medium was investigated over the pH range 2–3. The oxidation followed first order kinetics with [MnIII]. The effects of varying [MnIII], [NCS–], added MnII and metal ions, pH, total [P2O
f7
p4–
] and added ClO
f4
p–
, Cl– and SO
f4
p2–
were studied. The order in [NCS–] was unity, and increasing [H+] increased the rate. Retardations with added P2O
f7
p4–
and MnII were observed. Complexation of NCS– as K2Zn(NCS)4 decreased the reactivity without any change in overall mechanism. The dependence of the reaction rate on temperature was examined, and activation parameters were computed from Arrhenius and Eyring plots. A mechanism consistent with the results is proposed. 相似文献