Structure and Spectroscopic Studies of Cd(II) Complexes of Tris(2-pyridyl)amine: 1D and 2D Supramolecular Assemblies

2003 ◽  
Vol 68 (11) ◽  
pp. 2139-2149 ◽  
Author(s):  
Yong-Shu Xie ◽  
Xue-Ting Liu ◽  
Jia-Xiang Yang ◽  
Hui Jiang ◽  
Qing-Liang Liu ◽  
...  

Cd(II) halide complexes [Cd2X4(tpa)2] (1: X = Cl, 2: X = Br, 3: X = I; tpa = tris(2-pyridyl)amine) have been synthesized. X-Ray diffraction analyses of 2 and 3 reveal their asymmetrical dinuclear structures: one Cd(II) atom is octahedrally coordinated to four N atoms of two tpa ligands and two bridging halides; the other Cd(II) is tetrahedrally coordinated to two terminal (X(t)) and two bridging (X(b)) halides. By multiple intra- and intermolecular π-π interactions between the tpa pyridine rings, the ligands of 2 and 3 are linked to form a 2D network and 1D linear structures, respectively. In the Raman and far-infrared spectra, the absorption bands due to Cd-X(b) stretching modes lie at lower wavenumbers compared to the Cd-X(t) stretches. It can be inferred from the spectroscopic data that 1 has a dinuclear structure similar to those of 2 and 3.

1994 ◽  
Vol 47 (7) ◽  
pp. 1423 ◽  
Author(s):  
MAS Goher ◽  
AK Hafez ◽  
RJ Wang ◽  
XM Chen ◽  
TCW Mak

Complexes of the types HAuX4.2HQd, where X = Cl or Br and HQd = quinaldic acid, and AuX3L2, where L is methyl or ethyl quinaldate , have been prepared and characterized. Quinaldic acid as well as methyl and ethyl quinaldates function as monodentate ligands in these complexes, whose stereochemistries are discussed in relation to the number of gold-halogen stretching frequencies observed in their far-infrared spectra. The measured conductivities of these complexes are also discussed. Single-crystal X-ray analysis of monohydrated HAuBr4.2HQd revealed that it should be formulated as [( HQd )2H][AuBr4].H2O, in which a pair of zwitterionic HQd moieties are connected by a strong O...H...O hydrogen bond, and the gold(III) atom is in an elongated octahedral coordination environment with two long Au-O bonds of 3.388(8) and 3.440(8)Ǻ.


1998 ◽  
Vol 51 (4) ◽  
pp. 331 ◽  
Author(s):  
Graham A. Bowmaker ◽  
Frances M. M. Hannaway ◽  
Peter C. Junk ◽  
Aaron M. Lee ◽  
Brian W. Skelton ◽  
...  

Syntheses and room-temperature single-crystal X-ray determinations are recorded for a number of adducts of BiX3/N,N′-bidentate 1 : 2 stoichiometry (N,N′-bidentate = 2,2′-bipyridine (bpy) or 1,10-phenanthroline (phen)). BiX3/bpy (1 : 2), X = Br, I, are isomorphous, monoclinic, P21/c, a ≈ 7·5, b ≈ 31, c ≈ 10·3 Å, β ≈ 113°, Z = 4; conventional R on |F| were 0·058, 0·055 for No 1744, 2068 independent ‘observed’ (I > 3σ(I)) reflections. BiCl3/phen (1 : 2) is monoclinic, P21/C, a 9·675(3), b 31·845(7), c 7·756(2) Å, β 109·94(2), Z = 4, R 0·071 for No 2537, while BiBr3/phen (1 : 2), also monoclinic, P21/c, has a 17·590(5), b 8·812(2), c 17·537(7) Å, β 117·58(3)°, Z = 4; R 0·083 for No 890. BiX3/phen (1 : 2).S, X/S = Br/MeCN, I/CH2Cl2, are isomorphous, orthorhombic, Pna21, a ≈ 20·7, b ≈ 14·2, c ≈ 8·9 Å, Z = 4, R 0·060, 0·046 for No 1553, 2423 respectively. All complexes are mononuclear with seven-coordinate (N2)2BiX3 bismuth environments. Bands in the far-infrared spectra due to the v(BiX) vibrations in [(phen)2BiCl3] and [(bpy)2BiX3] (X = Br, I) are assigned and discussed in relation to the structures of the complexes.


1998 ◽  
Vol 51 (4) ◽  
pp. 325 ◽  
Author(s):  
Graham A. Bowmaker ◽  
Frances M. M. Hannaway ◽  
Peter C. Junk ◽  
Aaron M. Lee ◽  
Brian W. Skelton ◽  
...  

Room-temperature single-crystal X-ray studies are recorded for a number of adducts of BiX3 and N,N′-bidentate ligand (2,2′-bipyridine (bpy) or 1,10-phenanthroline (phen)), devoid of coordinated solvent. BiBr3/bpy/MeCN (1 : 1 : 1) is triclinic P-1, a 12·129(2), b 9·955(4), c 7·748(1) Å, α 73·14(2), β 77·34(1), γ 69·79(2)°, Z = 2; conventional R on |F| was 0·036 for No 2252 independent ‘observed’ (I > 3σ(I)) reflections. The phen analogue is isomorphous, a 11·586(3), b 10·839(6), c 7·769(10) Å, α 73·70(7), β 76·67(7), γ 70·34(4)°, Z = 2, R 0·042 for No 800. BiI3/bpy (1 : 1) is triclinic, P-1, a 11·742(4), b 9·261(1), c 8·261(3) Å, α 86·46(2), β 71·48(3), γ 67·25(2)°, Z = 2, R 0·043 for No 1164. All complexes are centrosymmetric binuclear [(N,N′-bidentate)X2Bi(µ-X)2BiX2(N,N′-bidentate)] with six-coordinate pseudo-octahedral bismuth(III). Attempts to produce a chloride analogue have resulted, in the case of N,N′-bidentate = bpy, in a novel adduct of BiCl3/bpy 1 : 1·5 stoichiometry, monoclinic, P21/c, a 9·377(8), b 17·699(5), c 21·58(1) Å, β 107·82(6)°, Z = 8, R 0·055 for No 1804. The complex is [(bpy)2Cl2Bi(µ-Cl)BiCl3(bpy)], containing seven- and six-coordinate bismuth. Bands in the far-infrared spectra due to the v(BiX) vibrations in [(bpy)2Cl2Bi(µ-Cl)BiCl3(bpy)] and [(bpy)I2Bi(µ-I2)BiI2(bpy)] are assigned and discussed in relation to the structures of the complexes.


Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3920
Author(s):  
Martin Weber ◽  
Gábor Balázs ◽  
Alexander V. Virovets ◽  
Eugenia Peresypkina ◽  
Manfred Scheer

By reacting [{Cp‴Fe(CO)2}2(µ,η1:1-P4)] (1) with in situ generated phosphenium ions [Ph2P][A] ([A]− = [OTf]− = [O3SCF3]−, [PF6]−), a mixture of two main products of the composition [{Cp‴Fe(CO)2}2(µ,η1:1-P5(C6H5)2)][PF6] (2a and 3a) could be identified by extensive 31P NMR spectroscopic studies at 193 K. Compound 3a was also characterized by X-ray diffraction analysis, showing the rarely observed bicyclo[2.1.0]pentaphosphapentane unit. At room temperature, the novel compound [{Cp‴Fe}(µ,η4:1-P5Ph2){Cp‴(CO)2Fe}][PF6] (4) is formed by decarbonylation. Reacting 1 with in situ generated diphenyl arsenium ions gives short-lived intermediates at 193 K which disproportionate at room temperature into tetraphenyldiarsine and [{Cp‴Fe(CO)2}4(µ4,η1:1:1:1-P8)][OTf]2 (5) containing a tetracyclo[3.3.0.02,7.03,6]octaphosphaoctane ligand.


2017 ◽  
Vol 72 (7) ◽  
pp. 461-474 ◽  
Author(s):  
Saddam Weheabby ◽  
Mohammad A. Abdulmalic ◽  
Evgeny A. Kataev ◽  
Tatiana A. Shumilova ◽  
Tobias Rüffer

AbstractPoly(cyclic) oxamates represent novel and potentially multidentate ligands for coordination chemistry. To obtain them, the treatment of 2-nitroaniline with two equivalents of oxalyl chloride afforded N,N′-bis(2-nitrophenyl)oxalamide (1), and by reduction of 1 with [NH4][CO2H] and Pd/C, N,N′-bis(2-aminophenyl)oxalamide (2, bapoxH6) was synthesized. After the addition of an equimolar amount of oxalyl chloride to a THF solution of 2 and aqueous work-up the 24-membered macrocycle H8L2 was obtained. In analogues experiments, the addition of ethoxalyl and oxalyl chloride to 2 afforded the 36-membered macrocycle H12L3. The addition of Cu(OAc)2·H2O and NaOH to 2 gave rise to the formation of [Cu2(bapoxH4)(OAc)2] (4). The identities of 1, 2 and H8L2 were determined by elemental analysis, IR, NMR spectroscopic studies and by mass spectrometry. The solid state structures of H8L2, H12L3 and 4 have been determined by single-crystal X-ray diffraction studies. Macrocycle H12L3 forms chains through intermolecular hydrogen bonds, while packing of 4 consists of layers held by intermolecular dispersion and hydrogen bond interactions. 24-mer H8L2 forms a cavity with a diameter of about 7.5 Å corresponding to an accessible volume of about 120 Å3 according to the well-established 55% solution and was found to bind bromide and iodide anions selectively.


1992 ◽  
Vol 45 (12) ◽  
pp. 2089 ◽  
Author(s):  
EL Ghisalberti ◽  
BW Skelton ◽  
AH White

The structure of the compound obtained on heating the naturally occurring clerodane furanoditerpene (1) had been formulated as (2) on the basis of spectroscopic studies. A single-crystal X-ray diffraction study on the dihydro derivative of (2) has confirmed this and provides support for the stereochemistry previously assigned to (1) on the basis of chemical evidence.


RSC Advances ◽  
2016 ◽  
Vol 6 (36) ◽  
pp. 30277-30284 ◽  
Author(s):  
Zhi-Wen Liu ◽  
Xiao-Jun Huang ◽  
Han-Lin Xiao ◽  
Guo Liu ◽  
Jian Zhang ◽  
...  

The structures and absolute configurations of seven new iboga-type alkaloids 1–7 were determined by spectroscopic data, Mosher's method, single crystal X-ray diffraction and ECD analyses.


1973 ◽  
Vol 27 (3) ◽  
pp. 213-217 ◽  
Author(s):  
Y. Saito ◽  
C. W. Schläpfer ◽  
M. Cordes ◽  
K. Nakamoto

The far infrared spectra of Ni (pyridine)4X2 and Ni(γ-picoline)4X2 (X = CI, Br and I) have been measured. The Ni-X and Ni-N stretching bands have been assigned based on isotopic shifts due to the 58Ni-62Ni, pyridine-pyridine-d5, and Cl-37Cl substitutions.


Author(s):  
Mateusz Gołdyn ◽  
Anna Komasa ◽  
Mateusz Pawlaczyk ◽  
Aneta Lewandowska ◽  
Elżbieta Bartoszak-Adamska

The study of various forms of pharmaceutical substances with specific physicochemical properties suitable for putting them on the market is one of the elements of research in the pharmaceutical industry. A large proportion of active pharmaceutical ingredients (APIs) occur in the salt form. The use of an acidic coformer with a given structure and a suitable pK a value towards purine alkaloids containing a basic imidazole N atom can lead to salt formation. In this work, 2,6-dihydroxybenzoic acid (26DHBA) was used for cocrystallization of theobromine (TBR) and caffeine (CAF). Two novel salts, namely, theobrominium 2,6-dihydroxybenzoate, C7H9N4O2 +·C7H5O4 − (I), and caffeinium 2,6-dihydroxybenzoate, C8H11N4O2 +·C7H5O4 − (II), were synthesized. Both salts were obtained independently by slow evaporation from solution, by neat grinding and also by microwave-assisted slurry cocrystallization. Powder X-ray diffraction measurements proved the formation of the new substances. Single-crystal X-ray diffraction studies confirmed proton transfer between the given alkaloid and 26DHBA, and the formation of N—H...O hydrogen bonds in both I and II. Unlike the caffeine cations in II, the theobromine cations in I are paired by noncovalent N—H...O=C interactions and a cyclic array is observed. As expected, the two hydroxy groups in the 26DHBA anion in both salts are involved in two intramolecular O—H...O hydrogen bonds. C—H...O and π–π interactions further stabilize the crystal structures of both compounds. Steady-state UV–Vis spectroscopy showed changes in the water solubility of xanthines after ionizable complex formation. The obtained salts I and II were also characterized by theoretical calculations, Fourier-transform IR spectroscopy (FT–IR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and elemental analysis.


2022 ◽  
Vol 1049 ◽  
pp. 218-223
Author(s):  
Aleksandr S. Kazachenko ◽  
Yuriy N. Malyar ◽  
Anna S. Kazachenko

Sulfated derivatives of polysaccharides have anticoagulant, hypolipedimic and other biological activity. In this work, a complex mixed ester of galactomannan, its sulfate-citrate, was obtained for the first time. The introduction of citrate and sulfate groups was proved by FTIR spectroscopy by the appearance of corresponding absorption bands. It was shown by X-ray diffraction that the introduction of the citrate group leads to the amorphization of the galactomannan structure.


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