The crystal structure of 1,3-dithiane 1,1,3,3-tetraoxide, C4H8O4S2, has been determined to examine the intermolecular C—H...O hydrogen bonds in a small molecule with highly polarized hydrogen atoms. The crystals are monoclinic, space group Pn, with a = 4.9472 (5), b = 9.9021 (10), c = 7.1002 (7) Å and β = 91.464 (3)° with Z = 2. The molecules form two stacks parallel to the a axis with the molecules being one a translation distance from each other. This stacking involves axial hydrogen atoms on one molecule and the axial oxygen atoms on the adjacent molecule in the stack. None of these C—H...O contacts is particularly short (all are > 2.4 Å). The many C—H...O contacts between the two stacks involve at least one equatorial hydrogen or oxygen atom. Again, no unusually short contacts are found. The whole crystal structure basically consists of a complex network of C—H...O contacts with no single, linear C—H...O contacts, only contacts that involve two (bifurcated), and mostly three or four neighbors.

The crystal structures of two crystalline phases of 1,4-dithiane 1,1,4,4-tetraoxide, C 4 H 8 O 4 S 2 , have been determined in order to examine the nature of possible intermolecular hydrogen bonds. Phase 1 is monoclinic, space group C 2/ m , with unit-cell dimensions of a = 9.073 (8), b = 7.077 (6), c = 5.597 (5) Å and β = 105.89 (1)°. The molecule adopts 2/ m symmetry and all of the molecules are related by translation and thus have the same orientation. Phase 2 is also monoclinic but in space group P 2 1 / n with unit-cell dimensions of a = 7.1305 (5), b = 5.7245 (4), c = 8.3760 (6) Å and β = 91.138 (2)°. In this phase, the molecule sits on an inversion center and the molecules within the unit cell adopt quite different orientations. In both phases, examination of the potential C—H...O hydrogen bonds around each of the independent oxygen atoms (one axial and the other equatorial) shows the general O...H patterns to be quite similar with each oxygen atom in contact with four neighboring H atoms, and each H atom contacting two neighboring O atoms. While none of the H...O contacts is particularly short (all are greater than 2.5 Å), each molecule has 32 such contacts that form an extensive intermolecular network. A 1 H NMR spectrum of the compound dissolved in DMSO shows a singlet of 8H at δ 3.677 which indicates that the C—H bonds are only moderately polarized by the single adjacent –SO 2 – moiety: strongly polarized C—H bonds have δ values in the 5–6 range [Li & Sammes (1983). J. Chem. Soc. Perkin Trans. 1 , pp. 1303–1309]. The phase 1 crystal studied was non-merohedrally twinned.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Due to disorder, [K(crypt-222)](+) CF3-(1) is crystallographically indistinguishable from its isomer, a 1:1 fluoroform clathrate of deprotonated [K(crypt-222)](+), [K(crypt-222{-H+})]CHF3 (2). In our preceding publications, 1 was characterized on the basis of combined X-ray diffraction, NMR, reactivity, labeling, acid-base, and DFT studies. Herein we report that neither incorporation of deuterium nor any other transformation of [K(crypt-222)](+) is observed in the presence of CD3OD/CD3OK at 70 degrees C or CD3S(O)CD2K/(D-6)DMSO at 23 degrees C over hours and even days. Since fluoroform is easily and quickly deprotonated under such conditions, the demonstrated greater acidity of CHF3 relative to [K(crypt-222)](+) provides additional evidence in favor of 1 and against 2. Likewise, crystal packing analysis and DFT calculations support 1, which has now been refined in the ultimately correct space group R32. Our previously drawn conclusions regarding [K(crypt-222)](+) CF3-and the existence of a naked' trifluoromethyl anion in a condensed phase remain valid. The recent alternative refinement (Becker and Muller, Chem. Eur. J. 2017, 23, 7081-7086) of our raw diffraction data has been improperly performed in the wrong space group to yield a non-charge-balanced model [K(crypt-222)]+CHF3, which is hereby repudiated. Becker and Muller's attempts to resolve the charge balance issue have produced models that are inadequate from the perspective of both crystallography and chemistry.

A crystallization method for 5-amidinium tetrazolide (1) was developed. Crystals of the pure zwitterion 1 enabled the unambiguous assignment of the structure as an inner-salt rather than the amidine tetrazole postulated previously. The solid-state structure of 1 consists of two sets of hydrogen bonds that form a tightly networked two-dimensional sheet. The reaction of amidinium tetrazolide 1 with SOCl2 in the presence of 2.0 equiv. of Et3N produces 3-amino-4-azido-1,2,5-thiadiazole (2) as the sole product. The required tetrazole ring-opening reactivity suggests that the tetrazole moiety may function as a masked geminal azido-nitrene. The thionyl chloride reaction with the amidinium zwitterion 1 occurs not exclusively at the amidine, but rather in the Bay-region of 1, which comprises both the amidinium group and tetrazolide ring. Thiadiazole 2 has a planar structure with a 2D network of hydrogen bonds between the amino group and nitrogen atoms and an S⋯N interaction between the azido group and sulfur.

Compounds with the composition Bi6(Bi1−yMy)X2O16−z, M=transition metal or Pb, X=P, V, As, display pseudo-tetragonal crystal systems. They are, however, monoclinic with space group I2 and the heavy atom positions mimic the δ-Bi2O3 structure. The title compound is monoclinic, a=11.284(2)Å, b=5.4259(11)Å, c=11.112(2)Å, β=96.25(3)°, I2, Z=2. Least-squares refinement of single-crystal X-ray diffraction data on F2 converged to R1=0.050, wR2=0.130. The crystal is twinned by two-fold rotation about [010] and each twin consists of its inverted component forming a racemate. The structure consists of chains of edge sharing (OBi4) tetrahedra parallel to [10−1]. The chains are bridged parallel to [101] by linked PO4 tetrahedra and (Mn/Bi)O6 octahedra parallel to [10−1], into a three-dimensional structure. The lone-pair electrons of adjacent Bi atoms along the chain point in opposite directions along the b-axis. The Bi atoms are in distorted trigonal prismatic coordination that has one or two faces capped. The BiO bond lengths vary from 2.08(5) to 3.05(2)Å. The Mn/Bi atoms are disordered around the two-fold axis. Three oxygen atom sites contain vacancies.

The title compound crystallizes in the tetragonal system, a = 11.733(2) Å, c = 15.587(3) Å, I4 mm, Z = 10. Data were collected at the Argonne National Laboratory synchrotron source at λ = 0.15359 Å. Least squares refinement on F2 converged to R1 = 0.039. The oxygen coordination polyhedra around Bi and Pb display the distortions typical of 6s2 lone-pair atoms. One Bi is disordered. BiO bonds vary from 2.08(2) to 2.96(1) Å. One Pb is in cubic coordination to oxygen and the second Pb is bonded to six oxygen atoms that form a rectangular pyramid and a seventh oxygen is off one of the rectangular faces of the pyramid. PbO bonds vary from 2.303(6) to 2.804(17) Å. Of the two crystallographically independent P one is in a single tetrahedral coordination while the second is at the center of two disordered tetrahedra. Units of OM4 tetrahedra, M = Bi/Pb, articulate into a three-dimensional framework by corner and edge sharing that is strengthened by corner sharing with PO4 moieties.

We have determined the crystal structures and superconducting transition temperatures of La1.48Nd0.4Sr0.12CuO4 under nearly hydrostatic pressures in diamond anvil cells to 5.0 GPa and 19.0 GPa, respectively. Synchrotron x-ray powder diffraction measurements were used to establish the pressure-temperature structural phase diagram. Under pressure the superconducting transition temperature increases rapidly from Tc = 3 K to a maximum value of 22 K at 5 GPa, a pressure slightly greater than that required to stabilize the undistorted I4/mmm structure in the superconducting state. Increasing the pressure further to 19 GPa leads to a decrease in Tc to ~12 K. These results are discussed in relation to earlier high pressure measurements for similar materials.

The title compound crystallizes in the tetragonal system, a = 11.733(2) angstrom, c = 15.587(3) angstrom, I4 mm, Z = 10. Data were collected at the Argonne National Laboratory synchrotron source at lambda = 0.15359 angstrom. Least squares refinement on F-2 converged to R1 = 0.039. The oxygen coordination polyhedra around Bi and Pb display the distortions typical of 6s(2) lone-pair atoms. One Bi is disordered. Bi-O bonds vary from 2.08(2) to 2.96(1) angstrom. One Pb is in cubic coordination to oxygen and the second Ph is bonded to six oxygen atoms that form a rectangular pyramid and a seventh oxygen is off one of the rectangular faces of the pyramid. Pb-O bonds vary from 2.303(6) to 2.804(17) angstrom. Of the two crystallographically independent P one is in a single tetrahedral coordination while the second is at the center of two disordered tetrahedra. Units of OM4 tetrahedra, M = Bi/Pb, articulate into a three-dimensional framework by corner and edge sharing that is strengthened by comer sharing with PO4 Moieties. (c) 2005 Elsevier Ltd. All rights reserved.

1DuPont Company, Central Research and Development, Wilmington, Delaware 19880-0356, USA 2Department of Physics, Washington University, St. Louis, Missouri 63130-4899, USA 3National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA 4Department of Physics, Brookhaven National Laboratory, Upton, New York 11973, USA 5Department of Physics, University of Tokyo, Tokyo 113-8656, Japan 6NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA sReceived 15 December 2004; published 24 March 2005 d

The formation of products derived from competing reactions in Rh-catalyzed alkene hydroborations prompted us to study in situ interactions of several hydroborating reagents with unsaturated phosphinorhodium complexes. The reaction of [Rh(μ-H)(DiPPE)]2 (1) with borane–dimethylsulfide gave several rhodium–boron containing products including the structurally characterized metallaborane [RhH(DiPPE)]2B3H7 (2) [DiPPE=1,2-bis(diisopropylphosphino)ethane]. Addition of thexylborane and 9-H-BBN dimers, containing alkyl groups, to 1 gave the corresponding mononuclear substituted borohydride complexes Rh(η2-H2BRR′)(DiPPE) (4: R=H, R′=C(CH3)2CH(CH3)2; 5: R,R′=bicyclo-[3.3.1]-nonane [C8H14]). The analogous monodentate phosphine complex Rh(η2-H2BC8H14)(PPri3)2 (6) was isolated and structurally characterized. Addition of catecholborane (HBcat; cat=1,2-O2C6H4) to 1 gave the unusual dinuclear species Rh(DiPPE)(μ-H)2(μ-Bcat)RhH(DiPPE) (7) containing a semi-bridging Bcat group, confirmed by single-crystal X-ray diffraction, and zwitterionic Rh(η6-catBcat)(DiPPE) (8). Implications for rhodium-catalyzed hydroborations are addressed.

Submitted for the MAR05 Meeting of The American Physical Society A Study of the Magnetic Properties of the Frustrated Spinels GeNi2O4 and GeCo2O4 M.K. CRAWFORD, R.L. HARLOW, R. FLIPPEN, DuPont, Wilmington, DE, S. HARA, Y. YOSHIDA, S.I. IKEDA, AIST, Tsukuba, Japan, Q. HUANG, J.W. LYNN, Y. QUI, J.R.D. COPLEY, Y. CHEN, NIST, Gaithersburg, MD, R.W. STEVENS, California Institute of Technology, Pasadena, CA, B.F. WOODFIELD, J. BOERIO-GOATES, Brigham Young University, Provo, UT, P.L. LEE, Y. ZHANG, APS, ANL, Argonne, IL, J. HORMADALY, Ben Gurion University, Beer Sheeva, Israel, R.A. FISHER, LBNL, Berkeley, CA — The spinels GeNi2O4 and GeCo2O4, in which the spin-1 Ni 2+ or spin-3/2 Co2+ ions are located on the vertices of a lattice of corner-sharing tetrahedra, exhibit interesting magnetic and structural properties. GeNi2O4 has a double Néel transition (TN1 = 12.13 K and TN2 = 11.46 K), but the crystal structure remains cubic in the Néel state. In contrast, GeCo2O4has a single Néel transition (TN = 20.6 K) that coincides closely with a cubic to tetragonal structural phase transition, below which c/a > 1. In the past we have used magnetic susceptibility, heat capacity, synchrotron x-ray, and neutron powder diffraction to study these materials. In this talk we will describe selected recent results of elastic and inelastic neutron scattering measurements of polycrystalline and single crystalline samples, the latter grown by the floating zone technique at AIST. Michael Crawford DuPont Company Date submitted: 30 Nov 2004 Electronic form version 1.4