The 119Sn Mössbauer and solid-state NMR and the crystal and molecular structure of tin(II) bisfluorosulfate, Sn(OSO2F)2

1991 ◽  
Vol 69 (12) ◽  
pp. 2122-2126 ◽  
Author(s):  
David C. Adams ◽  
Thomas Birchall ◽  
Romolo Faggiani ◽  
Ronald J. Gillespie ◽  
John E. Vekris

The reaction of tin(II) fluoride with fluorosulfuric acid has been shown to produce tin(II) bisfluorosulfate. Crystals of Sn(OSO2F)2 are monoclinic, space group P21/c with a = 5.195(1), b = 9.709(1), c = 13.861(1) Å, β = 110.12(1)°, Z = 4, R = 0.029, and Rw = 0.030 for 1461 unique reflections. The structure consists of a three-dimensional framework of fluorosulfate groups linked by O—Sn—O bridges with the two crystallographically independent fluorosulfates acting as tridentate bridging ligands between tin atoms. There are four short bonds (Sn—O = 2.338(3), 2.350(3), 2.398(4), and 2.427(3) Å) and two longer ones (Sn—O = 2.695(3) and 2.702(3) Å) around tin. The four short bonds have a disphenoidal, AX4E, primary geometry with the lone pair occupying an equatorial site. If the two longer interactions are also considered the geometry is distorted octahedral, AX4Y2E. Two more non-bonding contacts of 3.420(4) and 3.319(4) Å complete an approximately dodecahedral arrangement of oxygen atoms around the tin. The fluorosulfate groups deviate significantly from C3υ symmetry and have the mean dimensions, S(1)—O = 1.419(4), S(1)—F = 1.541(4), S(2)—O = 1.435(3), S(2)—F = 1.539(3) Å, O—S(1)—O = 114.3(2)°, F—S(1)—O = 104.1(3)°, O—S(2)—O = 114.2(2)°, and F—S(2)—O = 104.1(2)°, respectively. The solid-state 119Sn nmr spectrum shows only one single resonance with a shift of −1534 ppm which is substantially different from that of a solution in HSO3F. The 119Sn Mössbauer spectrum shows an unresolved quadrupole splitting as a result of a distorted environment around tin, produced by the stereochemically active non-bonding electron pair. Key words: tin(II) bisfluorosulfate, 119Sn Mössbauer, solid-state nmr, X-ray crystallography

1992 ◽  
Vol 47 (1) ◽  
pp. 139-143 ◽  
Author(s):  
Mohamed A. S. Goher ◽  
Morsy A. M. Abu-Youssef ◽  
Franz A. Mautner

The structures of mer-Cr(py)3(N3)3 (1) and polymeric NaCr(py)4(N3)4 (2) were determined by X-ray crystallography. Crystal data; 1, C15H15N12Cr, triclinic, space group P1̄, a = 895.3(2), b = 999.1(3), c = 1269.9(5) pm , α = 106.76(3), β = 96.69(3), γ = 116.30(2)°, V = 943.8(6) · 106 pm3, Z = 2 and Rw = 0.038 for 1736 observed MoKα diffractometer data; 2, C20H20N16CrNa, monoclinic, space group C2/c, a = 1561.2(3), b = 1028.8(2), c = 1573.6(4) pm, β = 90.70(2)°, V = 2 527.3(9) · 106 pm3, Z = 4 and = 0.033 for 1272 MoKα diffractometer data.The coordination around the chromium (III) ion in the discrete molecules of 1 is six-coordinate with mean distances Cr-N(py) of 210.2(4) pm and Cr-N(N3) of 200.8(4) pm. The terminal azido ligands are almost linear and asymmetric, the N-N bonds nearer to the metal (118.8(6) to 120.5(7) pm) being significantly longer than the terminal ones (114.7(7) to 115.5(7) pm). In compound 2, each chromium or sodium cation is six-coordinated by four azido groups and two pyridine molecules. The azido groups act as μ(1,3) bridging ligands between chromium and sodium octahedra to form a three-dimensional network structure. The chromium atoms are trans-coordinated by the pyridine ligands whereas the sodium cations are cis-coordinated.


1980 ◽  
Vol 58 (10) ◽  
pp. 1042-1045 ◽  
Author(s):  
R. L. Parkes ◽  
N. C. Payne ◽  
E. O. Sherman

An air-stable, red, crystalline, N-bonded acetonitrile complex of Os(III), OsCl3(NCCH3)(P(C6H5)3)2, has been prepared and characterized by elemental analysis, magnetic susceptibility, and a single crystal X-ray structure determination. Crystals are monoclinic, space group P21/c, cell dimensions a = 10.029(2), b = 15.233(2), c = 25.246(4) Å, β = 113.65(1)°, and Z = 4. Three dimensional X-ray diffraction intensity data were collected on an automatic four circle diffractometer using Cu radiation. Full-matrix least-squares refinement on F converged at R = 0.038 for 4384 unique observations. The Os atom has a slightly distorted octahedral coordination geometry, with trans phosphine ligands, mean Os—P 2.406(2) Å. The acetonitrile ligand is σ-bonded through the N atom, Os—N 2.038(6) Å. The bond trans to the acetonitrile ligand. Os—Cl(1) 2.364(2) Å, is not significantly different from the mean of the cisOs—Cl bonds, 2.361(2) Å.


1993 ◽  
Vol 48 (10) ◽  
pp. 1372-1380 ◽  
Author(s):  
M. Schmidt ◽  
K. Albert ◽  
R. Brindle ◽  
C. Maichle-Mössmer ◽  
K. Eger

The structure of (5H)-2-Amino-3-hydroxy-5-phenyl-furan-4-one (lb) was determined by NMR-spectroscopy in solution and in the solid state. The structure of its oxidation product, 3,4-Dihydro-3,3,4,4-tetrahydroxy-5-phenyl-furan-2(5H)-one (7), given in the literature as 5-Phenyl-2,3,4-(5H)-furan-trione, was determined by NMR spectroscopy and crystal structure analysis. The solid state NMR spectrum of 7 was compared to the spectrum of dehydroascorbic acid


1992 ◽  
Vol 47 (12) ◽  
pp. 1754-1758 ◽  
Author(s):  
M. A. S. Goher ◽  
M. A. M. Abu-Youssef ◽  
F. A. Mautner ◽  
H. P. Fritzer

The structures of two polymeric complexes of chromium(III) azide with pyridine, KCr(py)4(N3)4 (1), and RbCr(py)3(N3)4 (2), were determined by X-ray crystallography. Crystal data: 1, C20H20N16CrK, monoclinic, space group C2/c, a = 1611.2(5), b = 1050.6(3), c = 1609.0(5) pm, β = 91.69(3)°, Ζ = 4 and Rw = 0.037 for 923 diffractometer data; 2, C15H15N15CrRb, monoclinic, space group P21/n, a = 1311.9(3), b = 1139.0(4), c = 1523.3(4) pm, β = 109.39(2)°, Ζ = 4 and Rw = 0.046 for 2336 data.The crystal structure of 1 contains six-coordinated chromium and potassium cations with two pyridine ligands and four µ(1,3) bridging azido groups forming a three-dimensional network structure. The chromium atoms are trans-coordinated by the pyridine ligands, whereas the potassium cations are cis-coordinated. The polymeric complex 2 features di-µ(l,1,3) azido bridged CrRbN2 rings, distorted octahedral chromium(III) coordination geometry, sevencoordinated rubidium, and di-μ(1,3) azido bridges which link the binuclear RbCr(pyridine)3(N3)2 moieties into infinite chains parallel to the b axis.


1971 ◽  
Vol 49 (3) ◽  
pp. 468-476 ◽  
Author(s):  
Lilian Y. Y. Chan ◽  
F. W. B. Einstein

The crystal structure of potassium hydrogen di-iodate (bi-iodate) KIO3.HIO3 was determined from three dimensional X-ray data collected by counter methods. The structure was refined by full-matrix least-squares techniques to a conventional R factor of 5.0 % for the 1392 observed reflexions. The salt crystallizes in the monoclinic space group P21/c with eight formula units in a cell of dimension a = 7.028(1) Å, b = 8.203(1) Å, c = 21.841(3) Å, β = 98.03(1)°.The iodate units are all basically pyramidal; weak interionic I—O contacts complete a very distorted octahedral environment around three iodine atoms. There is a capped octahedral (7-coordinate) environment around the remaining iodine atom. The I—O bonds are in the range 1.75–1.82 Å and the I—OH bonds are 1.91 and 1.95 Å, variations in length can be correlated with differences in the degree of involvement in (a) hydrogen bonding and (b) interaction with adjacent iodine atoms.


2015 ◽  
Vol 1 (11) ◽  
pp. e1501087 ◽  
Author(s):  
Chaowei Shi ◽  
Pascal Fricke ◽  
Lin Lin ◽  
Veniamin Chevelkov ◽  
Melanie Wegstroth ◽  
...  

Bactofilins are a recently discovered class of cytoskeletal proteins of which no atomic-resolution structure has been reported thus far. The bacterial cytoskeleton plays an essential role in a wide range of processes, including morphogenesis, cell division, and motility. Among the cytoskeletal proteins, the bactofilins are bacteria-specific and do not have a eukaryotic counterpart. The bactofilin BacA of the speciesCaulobacter crescentusis not amenable to study by x-ray crystallography or solution nuclear magnetic resonance (NMR) because of its inherent noncrystallinity and insolubility. We present the atomic structure of BacA calculated from solid-state NMR–derived distance restraints. We show that the core domain of BacA forms a right-handed β helix with six windings and a triangular hydrophobic core. The BacA structure was determined to 1.0 Å precision (heavy-atom root mean square deviation) on the basis of unambiguous restraints derived from four-dimensional (4D) HN-HN and 2D C-C NMR spectra.


2009 ◽  
Vol 87 (1) ◽  
pp. 348-360 ◽  
Author(s):  
Bryan A Demko ◽  
Roderick E Wasylishen

A 31P and 77Se solid-state NMR investigation of the iminobis(diorganophosphine chalcogenide) HN(R2PE)2 (R = Ph,iPr; E = O, S, Se) systems is presented. The NMR results are discussed in terms of the known HN(R2PE)2 structures available from X-ray crystallography. The phosphorus chemical shift tensors are found to be sensitive to the nature of the alkyl and chalcogen substituents. The nature of the R group also influences the selenium chemical shift tensors of HN(R2PSe)2 (R = Ph, iPr), which are shown to be sensitive to hydrogen bonding in the dimer structure of HN(Ph2PSe)2 and to the presence of disorder in the case of HN(iPr2PSe)2. Scalar relativistic ZORA DFT nuclear magnetic shielding tensor calculations were performed yielding the orientations of the corresponding chemical shift tensors. A theoretical investigation into the effect of the E-P···P-E “torsion” angle on the phosphorus and selenium chemical shift tensors of a truncated HN(Me2PSe)2 system indicates that the electronic effect of the alkyl group on the respective nuclear magnetic shielding tensors are more important than the steric effect of the E-P···P-E torsion angle.Key words: iminobis(diorganophosphine chalcogenide), solid-state NMR, 31P NMR, 77Se NMR, ZORA DFT.


2008 ◽  
Vol 63 (12) ◽  
pp. 1357-1360 ◽  
Author(s):  
Gang Chen

Hydrothermal reaction of Zn(NO3)2 · 6H2O and 2-hydroxypyridine-3-carboxylic acid afforded a novel supramolecular complex, [Zn(C6H4NO3)2(H2O)2] (1). The complex has been characterized by macroanalysis, IR spectra, and thermogravimetric and differential thermal analysis (TG/DTA). Single crystal X-ray analysis shows that complex 1 crystallizes in the monoclinic space group P21/c with the cell dimensions a = 7.534(6), b = 12.289(1), c = 7.534(6) Å, β = 100.51°, V = 685.85(1) Å3, and Z = 2. The six-coordinated Zn atom is in a severely distorted octahedral geometry. The complex molecules are assembled via strong O-H· · ·O and N-H· · ·O hydrogen bonding interactions into a three-dimensional supramolecular framework. Compared with the free ligand, complex 1 exhibits strong fluorescence in the solid state at room temperature.


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