scholarly journals Synthesis, X-ray Crystal Structure, and Photochromism of a Sandwich-Type Mono-Aluminum Complex Composed of Two Tri-Lacunary α-Dawson-Type Polyoxotungstates

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2383
Author(s):  
Chika Nozaki Kato ◽  
Daichi Kato ◽  
Toshifumi Kashiwagi ◽  
Shunpei Nagatani

The synthesis and molecular structure of a dimeric, mono-aluminum complex composed of two tri-lacunary α-Dawson polyoxometalates, [H14Al(B-α-P2W15O56)2]7− (1), is described herein. The tetra-n-butylammonium salt of 1, [(n-C4H9)4N]7[H14Al(B-α-P2W15O56)2] (TBA-1) was prepared by passing an aqueous solution of K6[B-α-H3P2W15O59{Al(OH2)}3]⋅14H2O through an ion-exchange resin column (H+-form), followed by addition of tetra-n-butylammonium bromide. Analytically pure and colorless crystals of TBA-1 were obtained via vapor diffusion from acetonitrile/methanol at ~25 °C. Single-crystal X-ray structure analysis revealed that a six-coordinate aluminum ion was sandwiched between two tri-lacunary α-Dawson-type units, resulting in an overall C2h symmetry. The characterization of TBA-1 was accomplished by elemental analyses, thermogravimetric/differential thermal analyses, Fourier-transform infrared spectroscopy, and solution 31P nuclear magnetic resonance spectroscopy. The photochromic properties of TBA-1 were also characterized in methanol under light irradiation (λ = 365 nm and ≥400 nm).

2007 ◽  
Vol 62 (6) ◽  
pp. 823-828
Author(s):  
Okan Zafer ◽  
Hümeyra Paşaoğlub ◽  
O. Ozan Yılan ◽  
Orhan Büyükgüngör

New salts of 2-hydroxyaniline and 2-amino-3-hydroxypyridine with squaric acid were synthesized and characterized by elemental analyses, IR spectroscopy and thermal analyses (TG, DTG and DTA). The crystal structures of bis(2-hydroxyanilinium) squarate, [(C6H8NO+)2(C4O4)2−] (1) and bis(2- amino-3-hydroxy-pyridinium) squarate dihydrate, [(C5H7N2O+)2(C4O4)2−] · 2 H2O (2) were determined by single crystal X-ray diffraction. Both compounds crystallize in the monoclinic system, space group P21/c. The organic ammonium squarates decompose in two thermal steps


e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Saeed Zahmatkesh ◽  
Abdol Reza Hajipour

AbstractPyromellitic dianhydride (1) was reacted with L-leucine (2) to result in [N,N'-(pyromellitoyl)-bis-L-leucine diacid] (3). This compound (3) was converted to N,N'-(pyromellitoyl)-bis-L-leucine diacid chloride (4) by reaction with thionyl chloride. The microwave-assisted polycondensation of this diacid chloride (4) with polyethyleneglycol-diol (PEG-200) and/or three synthetic bisphenols furnish a series of new PEIs and Co-PEIs in a laboratory microwave oven (Milestone). The resulting polymers and copolymers have inherent viscosities in the range of 0.31- 0.53 dl g-1. These polymers are optically active, thermally stable and soluble in polar aprotic solvents such as DMF, DMSO, NMP, DMAc and sulfuric acid. All of the above polymers were fully characterized by IR spectroscopy, 1H NMR spectroscopy, elemental analyses, specific rotation and thermal analyses. Some structural characterizations and physical properties of these optically active PEIs and Co-PEIs are reported.


Polyhedron ◽  
2020 ◽  
Vol 188 ◽  
pp. 114694
Author(s):  
Na Xia ◽  
Wenjing Wan ◽  
Siming Zhu ◽  
Huan Wang ◽  
Kouame Ally

2008 ◽  
Vol 5 (s1) ◽  
pp. 1021-1024 ◽  
Author(s):  
K. C. Dey ◽  
V. Sharma

Sodium salts of copper substituted heteropoly compounds having molecular formula Na10[CuIIWVI6O24].22H2O(1) and Na10[CuIIMoVI6O24]. 19H2O(2) analogous to the Anderson type anion [Xn+M6O24]─(12-n)were synthesized according to the literature method. Compound(1) was synthesized from aqueous acidic solution containing sodium tungstate and copper chloride and compound(2) from sodium molybdate and copper chloride solution. The elemental analyses show 1:6 atomic ratio of the heteroatom to the addenda in both the compounds. The IR spectra for both the compounds are in good agreement with the reported formulae. A small deviation in IR spectra are observed than that established for Keggin anions. CuO6acts as hetero group which replaces MO6(M=W or Mo) from the Anderson structure. The thermal analyses of the compounds show the loss of the peripheral water molecules. The molecular weight of the compound (1) and (2) have been found as 2212.5 and 1600.5 respectively.


1993 ◽  
Vol 294 (3) ◽  
pp. 899-908 ◽  
Author(s):  
I B Coutinho ◽  
D L Turner ◽  
J LeGall ◽  
A V Xavier

Complete assignment of the aromatic and haem proton resonances in the cytochromes c3 isolated from Desulfovibrio baculatus strains (Norway 4, DSM 1741) and (DSM 1743) was achieved using one- and two-dimensional 1H n.m.r. Nuclear Overhauser enhancements observed between haem and aromatic resonances and between resonances due to different haems, together with the ring-current contributions to the chemical shifts of haem resonances, support the argument that the haem core architecture is conserved in the various cytochromes c3, and that the X-ray structure of the D. baculatus cytochrome c3 is erroneous. The relative orientation of the haems for both cytochromes was determined directly from n.m.r. data. The n.m.r. structures have a resolution of approximately 0.25 nm and are found to be in close agreement with the X-ray structure from D. vulgaris cytochrome c3. The proton assignments were used to relate the highest potential to a specific haem in the three-dimensional structure by monitoring the chemical-shift variation of several haem resonances throughout redox titrations followed by 1H n.m.r. The haem with highest redox potential is not the same as that in other cytochromes c3.


2014 ◽  
Vol 67 (7) ◽  
pp. 1021 ◽  
Author(s):  
Sonya K. Adas ◽  
Jesus A. Ocana ◽  
Scott D. Bunge

The addition of either lithium dimethylamide or lithium diethylamide to a tetrahydrofuran (THF) solution of 1,3-dicyclohexylcarbodiimide yielded THF adducts of lithium 2,2-dimethyl-1,3-dicyclohexylguandidinate (1) and lithium 2,2-diethyl-1,3-dicyclohexylguandidinate (2), respectively. One equivalent of either 1 or 2 was subsequently reacted with one equivalent of Group 11 halide (CuCl, AgBr, and AuCl) to generate oligonuclear complexes with the general formula {M[CyNC(NR2)NCy]}n where M, R, and n are respectively Cu, CH3, 2 (3); Cu, CH2CH3, 2 (4); Ag, CH3, 3 (5); Ag, CH2CH3, 3 (6); Au, CH3, 2 (7); and Au, CH2CH3, 2 (8). Compounds 1–8 were characterized by single-crystal X-ray diffraction. The bulk powders for all complexes were found to be in agreement with the crystal structures based on elemental analyses, Fourier transform infrared spectroscopy, and 1H, 13C, and 7Li NMR studies. The unique structural aspects of this family of Group 11 complexes are highlighted.


2021 ◽  
Vol 12 (3) ◽  
pp. 248-255
Author(s):  
Jahangir Mondal ◽  
Meman Sahu ◽  
Bhaskar Sharma ◽  
Rakesh Ganguly ◽  
Shubhamoy Chowdhury ◽  
...  

The synthesis and characterization of an imino-pyridyl ligand N,N'-(butane-1,4-diyl)bis(1-(pyridin-2-yl)methanimine) (L) and its Ag(I)ClO4 complex (I) by various spectroscopic techniques and elemental analyses is presented in this study. X-ray single crystal structure of complex I revealed that in complex I, each Ag(I) ion is tetra coordinated with two pyridine N-atoms and two imine N-atoms of the ligand L, forming a macrocyclic dimeric Ag(I) grid. In the macrocyclic dimer complex I, Ag-Ag separation along the chain is 5.318 Å. The Ag-Npy average distance is 2.396 Å and that of the Ag-Nim is 2.257 Å. The macrocyclic dimer complex I is supramolecularly arranged by π-stacking interactions. Computational, Hirshfeld surface analysis and photophysical studies on ligand L and complex I have also been performed. Crystal data for C32H36Ag2Cl2N8O8 (M =947.33 g/mol): Triclinic, space group P-1 (no. 2), a = 9.1714(12) Å, b = 10.4373(14) Å, c = 10.8297(14) Å, α = 112.317(3)°, β = 91.391(3)°, γ = 92.353(3)°, V = 957.3(2) Å3, Z = 1, T = 293.15 K, μ(MoKα) = 1.220 mm-1, Dcalc = 1.643 g/cm3, 10248 reflections measured (4.07° ≤ 2Θ ≤ 53.098°), 3966 unique (Rint = 0.0280, Rsigma = 0.0331) which were used in all calculations. The final R1 was 0.0722 (I > 2σ(I)) and wR2 was 0.2229 (all data).


2015 ◽  
Vol 70 (3) ◽  
pp. 165-169 ◽  
Author(s):  
Gao-Feng Wang

AbstractThe synthesis of two new copper(II) complexes with benzimidazole type ligands, Cu(tta)2(L1)2 (1) and Cu(tta)2(L1) (2) (where L1 is 3-(4-(1H-benzo[d]imidazol-1-yl)-4-methoxy phenyl)-1-phenylprop-2-en-1-one; tta is 2-thenoyltrifluoroacetonate), are reported. Their structures have been characterized by infrared spectroscopy, elemental analyses and single-crystal X-ray diffraction. The copper(II) ion of 1 is in a distorted octahedral environment, while that of 2 is in a distorted square-pyramidal environment. In both cases, the donor atoms are provided by oxygen atoms of the tta ligands and nitrogen atoms of the L1 ligands.


Sign in / Sign up

Export Citation Format

Share Document