ChemInform Abstract: Preparation and Crystal Structure of CsSb<sub>2</sub>Se<sub>4</sub>.

Sheldrick, William S.; Kaub, J.

doi:10.1002/chin.198643034

Cited by 16 publications

(18 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Lorentz and polarization effects. The structure was solved by direct methods using SHELXS, [19] all other calculations used CRYS-TALS. [20] Atomic scattering factors and anomalous dispersion terms were taken from ref.…”

Section: Methodsmentioning

confidence: 99%

Tricarbonyl-η6-[(2-thiophenyl)arene]- and -η6-[(2-thiophenyl)carbonylarene]- chromium Complexes: Preparation and Conformational Study

Prim

Tranchier

Rose‐Munch

et al. 2000

Eur. J. Inorg. Chem.

View full text Add to dashboard Cite

The cross coupling reaction of (p‐chloroanisole)tricarbonylchromium complex (1) with thiophene derivatives under palladium‐catalyzed conditions leads to the selective formation of tricarbonyl‐η6‐[(2‐thiophenyl)arene]‐ or ‐η6‐[(2‐thiophenyl)carbonylarene]chromium complexes (2 or 3) depending on reaction conditions. The conformation of complexes 2 and 3 in the solid state as well as in solution are reported.

show abstract

Section: Methodsmentioning

confidence: 99%

Tricarbonyl-η6-[(2-thiophenyl)arene]- and -η6-[(2-thiophenyl)carbonylarene]- chromium Complexes: Preparation and Conformational Study

Prim

Tranchier

Rose‐Munch

et al. 2000

Eur. J. Inorg. Chem.

View full text Add to dashboard Cite

show abstract

“…Reflections were measured from a hemisphere of data collected with each frame covering 0.38 in w. The solution, refinement and analysis of the single-crystal X-ray diffraction data was performed with the WinGX suite for small-molecule single-crystal crystallography. [43] The structure of 1 was solved by Patterson methods with DIRDIF 99 [44] and the structure of 2 was solved by direct methods with SHELXS-86, [45] and both were refined by full-matrix least-squares methods on F 2 with SHELXL-97. [46] The hydrogen atoms were included in calculated positions and refined with a riding mode, except hydrogen atoms bonded to the nitrogen atoms, which were found in a Fourier difference map and refined freely.…”

Section: Receptor Lmentioning

confidence: 99%

Protonated Macrobicyclic Hosts Containing Pyridine Head Units for Anion Recognition

Esteban‐Gómez

Platas‐Iglesias

Blas

et al. 2008

Chemistry A European J

View full text Add to dashboard Cite

In this paper, we report two macrobicyclic receptors containing pyridine head units derived from 1,10-diaza-15-crown[5] (L1) or 4,13-diaza-18-crown[6] (L2) that can be protonated in MeCN and used for anion recognition. The interaction of these protonated lateral macrobicycles with different anions has been investigated by means of spectrophotometric titrations in MeCN. The association constants for the complexes of halide anions with the protonated macrobicycles follow the sequences Cl(-)>Br(-)>I(-)>F(-) (L1) and Cl(-)>F(-)>I(-)>Br(-) (L2), whereby an increase of more than two logarithmic units is observed from F(-) to Cl(-) for the binding constants of the receptor derived from L1. The association constants also indicate an important degree of selectivity of these macrobicyclic receptors for Cl(-) over Br(-) or I(-). The X-ray crystal structure analyses of the chloride and bromide complexes confirms the formation of the envisaged supramolecular complexes. Moreover, the binding constants indicate that these receptors present a high sulfate-to-nitrate binding selectivity. The stability trend observed for the recognition of halide anions by the macrobicycles presented herein as well as the sulfate-to-nitrate binding selectivity have been rationalised by means of DFT calculations at the B3LYP/LanL2DZ level. These studies indicate that the especially high binding selectivity for Cl(-) is the result of the optimum fit between the protonated macrobicyclic cavity and the size of the anion, whereas the sulfate-to-nitrate selectivity results from shape complementarity between the hydrogen-binding acceptor sites on sulfate and the hydrogen-bond donors of the macrobicycle.

show abstract

“…A colorless needle of size 0.18 Â 0.22 Â 0.75 mm was grown from CHCl 3 and measured on a Bruker Smart 1000 CCD diffractometer with MoK a (l 0.71073 ä). The structure was solved by direct methods by means of SHELXS86 [32]. Non-H-atoms were refined anisotropically with SHELXL97 [33]; H-atoms were calculated at idealized positions and refined with isotropic displacement parameters: C 18 H 14 F 9 NO 2 S, M r 479.37, a 6.1579 (7) , T 133(2) K, w scans, scan width 0.38, 2.68 < 2q < 58.08.…”

mentioning

confidence: 99%

Study of Unusually High Rotational Barriers about SN Bonds in Nonafluorobutane‐1‐sulfonamides: The Electronic Nature of the Torsional Effect

Lyapkalo

Reißig

Schäfer

et al. 2002

Helvetica Chimica Acta

View full text Add to dashboard Cite

Dedicated to Professor Dieter Seebach on the occasion of his 65th birthday Slow rotation about the SÀN bond in N,N-disubstituted nonafluorobutane-1-sulfonamides 1 can easily be detected by NMR measurements at room temperature. This effect causes magnetic nonequivalence of otherwise identical geminal substituents in symmetrical staggered ground-state conformation A. The torsional barriers determined (62 ± 71 kJ ¥ mol À1 ) proved to be the highest ever observed for sulfonamide moieties. They are comparable to the values routinely measured for carboxylic acid amides or carbamates. The restricted rotation is interpreted as result (n N Àd S )-p and of n N Às* S;C interactions, which develop substantial S,N double-bond character in sulfonamides 1. The S,N binding interaction is increased by the highly electron-withdrawing effect of the perfluorobutyl group. The anticipated symmetry of the ground-state conformation A and the considerable shortening of the SÀN bond (1.59 ä) compared to the mean value in sulfonamides (1.63 ä) are confirmed by single-crystal X-ray study of N,N-dibenzylnonafluorobutane-1-sulfonamide (1c).Restricted rotation [1] is a well-known phenomenon for compounds I with single bonds YÀA that adopt considerable double-bond character due to the binding interactions of the electron-withdrawing p-system XY with the lone pair at A, as expressed by the dipolar mesomeric formula II (Scheme 1). This has been described for Y and A elements of the second row of the periodic table. Not surprisingly, the highest values of barriers to rotation are normally observed for compounds containing an amino group (A N), due to the very strong p-donating character of the N-atom. Hindered rotation of this type is well-documented, and the barriers to rotation have been measured for many classes of compounds [1] [2], including esters, nitrites, enamines, hydrazones, thio-and selenoamides, nitrosoamines, and triazenes [3]. Undoubtedly, carbamates and amides proved to be the most frequently occurring substances exhibiting atropisomerism about their CÀN bonds. Reviews on dynamic effects in amides and related compounds [2] [4] reflect the fundamental character and significance of this topic. Elements of the third (e.g., Si, P, S) and higher periods exhibit much lower tendencies to p-bond. As a consequence, the barriers to rotation in the

show abstract

ChemInform Abstract: Preparation and Crystal Structure of CsSb₂Se₄.

Abstract: The title phase is obtainable by hydrothermal reaction of Cs2CO3 with Sb2Se3 in a H2O suspension at 1 15°C within 10d. The structure of the novel compound (PT, Z=2) consists of (Sb2Se; )" anions, containing (Sb)Se‐Sb and (Sb)Se‐Se(Sb) bridges, and of Cs cations.

Cited by 16 publications

References 1 publication

Tricarbonyl-η6-[(2-thiophenyl)arene]- and -η6-[(2-thiophenyl)carbonylarene]- chromium Complexes: Preparation and Conformational Study

Tricarbonyl-η6-[(2-thiophenyl)arene]- and -η6-[(2-thiophenyl)carbonylarene]- chromium Complexes: Preparation and Conformational Study

Protonated Macrobicyclic Hosts Containing Pyridine Head Units for Anion Recognition

Study of Unusually High Rotational Barriers about SN Bonds in Nonafluorobutane‐1‐sulfonamides: The Electronic Nature of the Torsional Effect

Contact Info

Product

Resources

About

ChemInform Abstract: Preparation and Crystal Structure of CsSb2Se4.

Abstract: The title phase is obtainable by hydrothermal reaction of Cs2CO3 with Sb2Se3 in a H2O suspension at 1 15°C within 10d. The structure of the novel compound (PT, Z=2) consists of (Sb2Se; )" anions, containing (Sb)Se‐Sb and (Sb)Se‐Se(Sb) bridges, and of Cs cations.

Cited by 16 publications

References 1 publication

Tricarbonyl-η6-[(2-thiophenyl)arene]- and -η6-[(2-thiophenyl)carbonylarene]- chromium Complexes: Preparation and Conformational Study

Tricarbonyl-η6-[(2-thiophenyl)arene]- and -η6-[(2-thiophenyl)carbonylarene]- chromium Complexes: Preparation and Conformational Study

Protonated Macrobicyclic Hosts Containing Pyridine Head Units for Anion Recognition

Study of Unusually High Rotational Barriers about SN Bonds in Nonafluorobutane‐1‐sulfonamides: The Electronic Nature of the Torsional Effect

Contact Info

Product

Resources

About

ChemInform Abstract: Preparation and Crystal Structure of CsSb₂Se₄.