Structural characterization and Hirshfeld surface analysis of 2-iodo-4-(pentafluoro-λ6-sulfanyl)benzonitrile

The title compound, C7H3F5INS, a pentafluorosulfanyl (SF5) containing arene, was synthesized from 4-(pentafluorosulfanyl)benzonitrile and lithium tetramethylpiperidide following a variation to the standard approach, which features simple and mild conditions that allow direct access to tri-substituted SF5 intermediates that have not been demonstrated using previous methods. The molecule displays a planar geometry with the benzene ring in the same plane as its three substituents. It lies on a mirror plane perpendicular to [010] with the iodo, cyano, and the sulfur and axial fluorine atoms of the pentafluorosulfanyl substituent in the plane of the molecule. The equatorial F atoms have symmetry-related counterparts generated by the mirror plane. The pentafluorosulfanyl group exhibits a staggered fashion relative to the ring and the two hydrogen atoms ortho to the substituent. S—F bond lengths of the pentafluorosulfanyl group are unequal: the equatorial bond facing the iodo moiety has a longer distance [1.572 (3) Å] and wider angle compared to that facing the side of the molecules with two hydrogen atoms [1.561 (4) Å]. As expected, the axial S—F bond is the longest [1.582 (5) Å]. In the crystal, in-plane C—H...F and N...I interactions as well as out-of-plane F...C interactions are observed. According to the Hirshfeld analysis, the principal intermolecular contacts for the title compound are F...H (29.4%), F...I (15.8%), F...N (11.4%), F...F (6.0%), N...I (5.6%) and F...C (4.5%).

Dynamic Disorder of Fe3+ Ions in the Crystal Structure of Natural Barioferrite

A natural barioferrite, BaFe3+12O19, from a larnite–schorlomite–gehlenite vein of paralava within gehlenite hornfels of the Hatrurim Complex at Har Parsa, Negev Desert, Israel, was investigated by Raman spectroscopy, electron probe microanalysis, and single-crystal X-ray analyses acquired over the temperature range of 100–400 K. The crystals are up to 0.3 mm × 0.1 mm in size and form intergrowths with hematite, magnesioferrite, khesinite, and harmunite. The empirical formula of the barioferrite investigated is as follows: (Ba0.85Ca0.12Sr0.03)∑1(Fe3+10.72Al0.46Ti4+0.41Mg0.15Cu2+0.09Ca0.08Zn0.04Mn2+0.03Si0.01)∑11.99O19. The strongest bands in the Raman spectrum are as follows: 712, 682, 617, 515, 406, and 328 cm−1. The structure of natural barioferrite (P63/mmc, a = 5.8901(2) Å, c = 23.1235(6) Å, V = 694.75(4) Å3, Z = 2) is identical with the structure of synthetic barium ferrite and can be described as an interstratification of two fundamental blocks: spinel-like S-modules with a cubic stacking sequence and R-modules that have hexagonal stacking. The displacement ellipsoids of the trigonal bipyramidal site show elongation along the [001] direction during heating. As a function of temperature, the mean apical Fe–O bond lengths increase, whereas the equatorial bond lengths decrease, which indicates dynamic disorder at the Fe2 site.

Assessing covalency in equatorial U–N bonds: density based measures of bonding in BTP and isoamethyrin complexes of uranyl

N-donor complexes of uranyl have been investigated with density-based analytical methods in order to quantify equatorial bond covalency and its effect on axial U–Oyl bonding.

Interionic Force Model for Pentahalide Molecules and Higher Niobium-Based Halide Clusters

Molecular bound states tend to become progressively more stable in the melts of polyvalent metal halides as the nominal valence of the metal increases. We examine in this work the case of pentavalent metal halides. First we propose a simple ionic model for the binding in several pentahalide clusters: the chlorides of Nb, Ta, Sb, and Mo and the bromides of Nb and Ta. The molecular monomers of these compounds have a D3h trigonal-bipyramidal structure in the ground state, and we make use of data on equatorial bond lengths and breathing mode frequencies in the vapour to determine the main force-law parameters of the metal ion. We also find that the C4v square-pyramidal structure is mechanically unstable against transformation into the D3h shape.We then consider higher molecular clusters, i. e. the dimers of Nb pentahalides and the bound states formed by NbCl5 with the chlorides of Cs, Al, Ga, and Sb. We propose structural models for all these stable clusters and compare their calculated vibrational frequencies with the available data from vibrational spectroscopy of mixed melts.

The Deformation of Di-μμ-halide Dinuclear Five-Coordinate Copper(II) Complexes in the Crystalline State

The coordination geometries of 154 dinuclear di-\mu-chloro, di-\mu-bromo and di-\mu-fluoro five-coordinate (4 + 1) copper(II) complexes have been analyzed by the structural correlation method. Two reference CuII polyhedra have been established: (i) a trigonal bipyramid (TBP) in which the equatorial bond lengths are equal, but with the symmetry at the metal often deformed from D 3h to C 2, and (ii) an elongated square pyramid (SQP), with either a pyramidally or tetrahedrally distorted base, in which the trans valence angles are equal. Six different paths for the SQP⇌TBP deformation of the CuII coordination have been established from three criteria: (a) the location of the bridging ligands (axial and equatorial or equatorial and equatorial in TBP); (b) the nature of the deformation of the SQP base plane (pyramidal or tetrahedral); (c) whether a bridging or nonbridging bond is elongated in a SQP. The causes of the angular distortions from C 2 symmetry along the apical bond of a SQP, typical for the TBP⇌SQP Berry path, are analyzed. A progressive reduction of the tetragonal elongation of the Cu—D apical (SQP) bond length along the SQP⇌TBP transformation path and trigonal equalization of the three equatorial Cu—D (TBP) bonds are observed. The dependence of the average Cu—Cu′ distance and Cu—X—Cu′ angles on the deformation path are also established.

Darstellung und Kristallstruktur von K2Sn2S5 und K2Sn2Se5 / Preparation and Crystal Structure of K2Sn2S5 and K2Sn2Se5

K2Sn2S5 and K2Sn2Se5 were prepared by reacting stoichiometric powdered mixtures of the binary compounds K2S or K2Se with Sn and the corresponding chalcogen at 1070 K, followed by slow cooling of the melt. The two compounds are isostructural and crystallize with the Tl2Sn2S5 structure type, s.g. C 2/c, Z = 4 with a = 11.072(5) Å, b = 7.806(3)Å, c = 11.517(5)Å, β = 108.43(2)° for K2Sn2S5 and a = 11.613(5)Å, b = 8.189(3) Å, c = 11,897(6) Å, β = 108.28(2)° for K2Sn2Se5. The crystal structures were refined to conventional R-factors of 0.032 and 0.031, respectively. Sn-atoms are in a distorted trigonal-bipyramidal chalcogen coordination. The average equatorial bond lengths are Sn -S: 2.427 Å and Sn -Se: 2.552 Å , the axial ones are Sn -S: 2.600 Å and Sn -Se: 2.774 Å.

The crystal structure of W(CO)5piperidine: Implications for photoreactivity of W(CO)5L complexes

The X-ray crystal structure of W(CO)5piperidine is reported and assignments are given for the LF and CT band of W(CO)5piperidine and W(CO)5pyridine. The [Formula: see text](axial), and [Formula: see text] (equatorial) bond lengths for W(CO)5pip are 2.330(5), 1,963(6), and 2.04(7), respectively. The longer [Formula: see text] bond length in W(CO)5pip compared to W(CO)5pyr corresponds to greater photoreactivity observed under LF triplet excitation for W(CO)5pip but cannot account for the reverse trend observed under LF singlet irradiation. The structure also fails to support a model based on differences in π back donation from W. It is concluded that differences between singlet and triplet photoreaction originate in the relative rates of radiationless decay. Key words: W(CO)5piperidine, photoreactivity, crystal structure.

Kombinierte 3.3- und 3.4-Addition an ein 1.2.4.3λ3-Triazaphosphol zu Tricyclophosphoranen / Combined 3,3- and 3,4-Addition to a 1,2,4,3λ3-Triazaphosphole Yielding Tricyclic Phosphoranes

2-Methyl-5-phenyl-2H-1,2,4,3λ3-triazaphosphole, which does not lend itself to oxidative additions alone, reacts smoothly with o-heterodienyl-phenols yielding tricyclic phosphoranes. The reaction involves an initial addition of the phenolic end to the P=N bond and a subsequent fast intramolecular addition of the heterodiene moiety to the phosphorus.The structure of the resulting phosphoranes is proposed to have all three fivemembered rings attached to the central trigonal bipyramidal phosphorus by one axial and one equatorial bond with the bond in common to the two condensed rings in axial position. NMR data back this proposal.