Synthesis, Characterization and Crystal Structure of （Z）-1-[2-（Triarylstannyl）vinyl]-1-indanols and Their Arylhalostannyl Derivatives

(Z)-1-[2-(Tri-o-tolylstannyl)vinyl]-1-indanol (1) and (Z)-1-[2-(tri-p-tolylstannyl)vinyl]-l-indanol (2) were synthesized by the addition reaction of 1-ethynylindanol with tri-o-tolyltin and tri-p-tolyltin hydride. The aryl groups in compound 1 and 2 were substituted by Br2 or I2 to yield monohalide derivatives (3-6). The compounds 1-6 were characterized by elemental analysis, ^1H NMR and FT-IR spectroscopy. The crystal structures of 1, 2 and 4 have been determined by single crystal X-ray diffraction analysis. The Sn atom in 1 and 2 exhibits a tetrahedral geometry distorted towards trigonal bipyramid due to a weak intramolecular interaction between Sn and the hydroxyl O atoms [0.2839(4) nm and 0.2744(5) nm], while the Sn atom in 4 adopts a trigonal bipyramidal geometry with a significant O→Sn(1) interaction [0.2552(5) nm].     

Thermomorphic metal scavengers: A synthetic and multinuclear NMR study of highly fluorinated ketones and their application in heavy metal removal

The preparation of a ketone with two long chain perfluoroalkyl groups is reported via the coupling reaction of a perfluorinated alkylzinc reagent and a perfluoro-acid chloride. This ketone has been investigated in the heterogeneous removal of heavy metals M²⁺ (M = Sn, Cd, Pb, Hg) and As⁵⁺ from aqueous solutions and removal of these metals from organic solvents using the unique thermomorphic properties of the fluorous ketone. In addition, a comprehensive ¹³C NMR study of one of the intermediates in the synthesis, 2H,2H,3H,3H-perfluoronanoic acid, has allowed the determination of all ¹J_C-F and ²J_C-F coupling constants. Also reported is the crystal structure of the acid CF₃(CF₂)₅CH₂CH₂CO₂H.     

A novel heterobidentate chiral phosphine and its coordination chemistry in transition metal clusters

The optically active ligand R,R-PHAZAN (1,3-bis[(1R)-1-Phenylethyl]-2-(2-thienyl)-1,3,2-diazaphospholane) has been prepared and the products resulting from the reactions with Rh₆(CO)₁₅NCMe, H₃RhOs₃(CO)₁₂, and H₄Ru₄(CO)₁₂ have been investigated by X-ray crystallography and a variety of multinuclear NMR methods. X-ray studies show that PHAZAN can behave as a bidentate ligand in Rh₆(CO)₁₄(μ₂,κ²-R,R-PHAZAN) (with coordination through P and S) or a monodentate ligand (through P coordination) in H₄Ru₄(CO)₁₁(κ¹-R,R-PHAZAN) and NMR studies show that these structures are retained in solution. In Rh₆(CO)₁₄(μ₂,κ²-R,R-PHAZAN), edge-bridging coordination of PHAZAN results in the formation of an additional two novel chiral centres and these are observed in solution. Reaction of PHAZAN with H₃RhOs₃(CO)₁₂ results in cleavage of the thienyl group and formation of the phosphido cluster, H₂RhOs₃(CO)₁₁(μ₂-PNN), (PNN = 1,3-bis-(1-phenylethyl)-[1,3,2]diazaphospholidine-2-yl). A variety of NMR measurements show that the hydride site-occupancies in the solid state are retained in solution and there is evidence for interaction of an ortho-phenyl hydrogen and a hydride through “dihydrogen” bonding.     

Hypervalent Organoselenium(II) Compounds with Organophosphorus Ligands. Crystal and Molecular Structure of [2‐(iPr2NCH2)C6H4]Se[S2PR′2] (R′ = Ph,OiPr)

Redistribution reactions between diorganodiselenides of type [2‐(R₂NCH₂)C₆H₄]₂Se₂ [R = Et, iPr] and bis(diorganophosphinothioyl disulfanes of type [R′₂P(S)S]₂ (R = Ph, OiPr) resulted in the hypervalent [2‐(R₂NCH₂)C₆H₄]SeSP(S)R′₂ [R = Et, R′ = Ph ( 1 ), OiPr ( 2 ); R = iPr, R′ = Ph ( 3 ), OiPr ( 4 )] species. All new compounds were characterized by solution multinuclear NMR spectroscopy (¹H, ¹³C, ³¹P, ⁷⁷Se) and the solid compounds 1 , 3 , and 4 also by FT‐IR spectroscopy. The crystal and molecular structures of 3 and 4 were determined by single‐crystal X‐ray diffraction. In both compounds the N(1) atom is intramolecularly coordinated to the selenium atom, resulting in T‐shaped coordination arrangements of type (C,N)SeS. The dithio organophosphorus ligands act monodentate in both complexes, which can be described as essentially monomeric species. Weak intermolecular S ··· H contacts could be considered in the crystal of 3 , thus resulting in polymeric zig‐zag chains of R and S isomers, respectively.     

Bis-phenol A Cyclophanes: Synthesis, Crystal Structures and Binding Studies

The synthesis and structural characterisation of three new macrocyclicbis-phenol A cyclophane ethers are described. The solid state structuresof two of the cyclophanes were determined by single crystal X-raydiffraction. Cyclophane 3 crystallises in the orthorhombic spacegroup Pbca with unit cell dimensions of a = 11.533(7), b = 29.383(8),c = 14.927(8) Å and cyclophane 4 in the monoclinic spacegroup P2₁/n with cell dimensions of a = 11.585(4), b = 11.839(2), c = 18.866(2) Å, = 94.48(2)°.The X-ray crystalstructures reveal distorted conformations, thus supporting the weak bindingof quats in solution observed by the NMR studies. In the crystalline state bothmacrocycles were found to form self-complementary dimers held together byweak intermolecular - and CH- interactions. The bindingbehaviour towards a series of tetralkylammonium cations was determinedby ¹H NMR titration in CDCl₃ solution. The interactions between the hosts and the quats were clearly detectable but too weak to be translated into meaningful equilibrium constants.     

The synthesis, crystal structures and NMR spectroscopic investigation of 3,7,10-trimethylsilatranes and carbasilatranes

The first representatives of aryloxy-trimethylsilatranes, C₆H₅OSi[OCH(CH₃)CH₂]₃N, of aryloxy-carbasilatranes, C₆H₅OSi(CH₂CH₂CH₂)(OCH₂CH₂)₂N, and a number of novel 3,7,10-trimethylsilatranes (RSi[OCH(CH₃)CH₂]₃N) and carbasilatranes (RSi(CH₂CH₂CH₂)(OCH₂CH₂)₂N) have been prepared and characterised, both structurally and by NMR spectroscopy. The influence of various Si substituents (R = alkyl, aryl, alkoxy and aryloxy) as well as the influence of the substitution in the skeleton of the trimethylsilatranes and carbasilatranes on the chemical shift in the ²⁹Si, ¹H and ¹³C NMR spectra has been investigated. The crystal structures of both diastereomers of phenyl-3,7,10-trimethylsilatrane and of the symmetrical isomer of p-tolyl-3,7,10-trimethylsilatrane were determined by X-ray diffraction after separation of the diastereomers by means of HPLC. All three crystal structures are centrosymmetric.     

Biological chemistry of organotin compounds: Interactions and dealkylation by dithiols

In this paper, we review our past and current efforts toward the elucidation of the biological chemistry of organotin compounds. In particular, we cover two prominent aspects of organotin compounds: their reactivity toward biological dithiols, and their degradation (or metabolization) mechanism using a combination of experimental and computational techniques.     

First X-ray structural characterisation of host-guest interactions in tetra-tetrazole macrocycles

The syntheses of tetra-tetrazole macrocycles, containing two 1,3-bis(tetrazole)benzene units linked by a variety of n-alkyl (n=3, 5, 7 or 9 carbon atoms) chain lengths, are described. The crystal structures of two 1,3-bis(tetrazole)benzenes containing pendant bromoalkyl chains (n=3 or 5) are reported. A tetra-tetrazole macrocycle has also been structurally characterised and contains an unexpected ‘host-guest’ interaction through binding of a chloroform solvent molecule. The resulting deviation of the macrocycle from planarity results from a combination of the ‘host-guest’ interaction and strong intermolecular interactions between adjacent tetrazole and phenylene rings.     

Comparative structural analysis of a histone-like protein from Spiroplasma melliferum in the crystalline state and in solution

A solution of a histone-like protein from Spiroplasma melliferum (HUSpm) was examined by small-angle X-ray scattering (SAXS). The experimental SAXS curve was compared with those calculated for the HUSpm structures from the PDB databank obtained by both X-ray diffraction analysis and nuclear magnetic resonance spectroscopy. The model of the HUSpm structure in solution, which best agrees with the experimental SAXS data, has a shorter distance between the centers of mass of the HUSpm monomers compared to the crystal structure, indicating that the HUSpm monomers can be located closer to each other in solution than in the crystalline state.     

The asymmetric ONNO complexes of dioxouranium(VI) with N,N-diarylidene-S-propyl-thiosemicarbazones derived from 3,5-dichlorosalicylaldehyde: Synthesis, spectroscopic and structural studies

Two uranyl complexes having the composition [UO₂(L)DMSO] were synthesized using salicyl- and 3,5-dichlorosalicylaldehyde-S-propyl-thiosemicarbazones as starting materials. The S-propyl-thiosemicarbazidato structures in the complexes are N¹-3,5-dichlorosalicylidene-N⁴-salicylidene and N¹-salicylidene-N⁴-3,5-dichlorosalicylidene. The stable solid complexes were characterized by means of elemental analysis, IR and ¹H NMR spectroscopies, and the single crystal X-ray diffraction technique. The two complexes, with the same formula, crystallize in different space groups. In the title complexes, the uranium atom is seven-coordinated in a distorted pentagonal-bipyramidal geometry involving an ONNO donor set of the thiosemicarbazidato ligand and an oxygen atom of a DMSO molecule. The two apical positions of the pentagonal bipyramid are occupied by the two oxygen atoms of the trans-dioxouranium group. The relative orientations of the DMSO and S-propyl groups in both complexes are somewhat different due to different crystal packing.     

Tri(1-cyclohepta-2,4,6-trienyl)phosphan,P(C7H7)3 und Tetra(1-cyclohepta-2,4,6-trienyl)phosphonium-tetrafluoroborat, [P(C7H7)4]BF4

Tri(1-cyclohepta-2,4,6-trienyl)phosphane, P(C₇H₇)₃, and Tetra(1-cyclohepta-2,4,6-trienyl)phosphonium Tetrafluoroborate, [P(C₇H₇)₄]BF₄ The reaction of tris(trimethylsilyl)phosphane, P(SiMe₃)₃, with tropylium bromide, C₇H₇⁺Br^?, in polar solvents such as dichloromethane or tetrahydrofuran gives P(C₇H₇)₃ ( 1 ) and [P(C₇H₇)₄]Br ( 2a ). According to the X-ray crystallographic structure determinations, all 1-cyclohepta-2,4,6-trienyl substituents are present in the boat conformation in both P(C₇H₇)₃ ( 1 ) and the phosphonium salt, [P(C₇H₇)₄]BF₄ ( 2b ). The boat-shaped C₇H₇ rings are significantly more flattened if the phosphorus occupies the axial rather than the equatorial position at the ring substituent. Addition of a chalcogen to the lone pair at the central phosphorus atom of 1 leads to the chalcogena-phosphoranes EP(C₇H₇)₃ (E = O ( 3a ), S ( 3b ), Se ( 3c )). The new 1-cyclohepta-2,4,6-trienyl-phosphorus compounds 1, 2 b and 3a–c were characterized by their ¹H, ¹³C, and ³¹P NMR spectra in C₆D₆ solution.     

Structural and spectroscopic trends in mononuclear arylchalcogenolato-palladium(II) and -platinum(II) complexes: Crystal structures of [M(TeAr)2(dppe)] {M = palladium, platinum; Ar = phenyl, 2-thienyl; dppe = 1,2-bis(diphenylphosphino)ethane}

A series of mononuclear [M(EAr)₂(dppe)] [M = Pd, Pt; E = Se, Te; Ar = phenyl, 2-thienyl; dppe = 1,2-bis(diphenylphosphino)ethane] complexes has been prepared in good yields by the reactions of [MCl₂(dppe)] and corresponding ArE⁻ with a special emphasis on the aryltellurolato palladium and -platinum complexes for which the existing structural information is virtually non-existent. The complexes have crystallized in five isomorphic groups: (1) [Pd(SePh)₂(dppe)] and [Pt(SePh)₂(dppe)], (2) [Pd(TePh)₂(dppe)] and [Pt(TePh)₂(dppe)], (3) [Pd(SeTh)₂(dppe)], (4) [Pt(SeTh)₂(dppe)] and [Pd(TeTh)₂(dppe)], and (5) [Pt(TePh)₂(dppe)]. In addition, solvated [Pd(TePh)₂(dppe)] · CH₃OH and [Pd(TeTh)₂(dppe)] · 1/2CH₂Cl₂ could be isolated and structurally characterized. The metal atom in each complex exhibits an approximate square-planar coordination. The Pd-Se, Pt-Se, Pd-Te, and Pt-Te bonds span a range of 2.4350(7)-2.4828(7) Å, 2.442(1)-2.511(1) Å, 2.5871(7)-2.6704(8) Å, and 2.6053(6)-2.6594(9) Å, respectively, and the respective Pd-P and Pt-P bond distances are 2.265(2)-2.295(2) Å and 2.247(2)-2.270(2) Å. The orientation of the arylchalcogenolato ligands with respect to the M(E₂)(P₂) plane has been found to depend on the E-M-E bond angle. The NMR spectroscopic information indicates the formation of only cis-[M(EAr)₂(dppe)] complexes in solution. The trends in the ³¹P, ⁷⁷Se, ¹²⁵Te, and ¹⁹⁵Pt chemical shifts expectedly depend on the nature of metal, chalcogen, and aryl group. Each trend can be considered independently of other factors. The ⁷⁷Se or ¹²⁵Te resonances appear as second-order multiplets in case of palladium and platinum complexes, respectively. Spectral simulation has yielded all relevant coupling constants.     

Ionic Dissociation of SiCl4: Formation of [SiL6]Cl4 with L=Dimethylphosphinic Acid

Reactions of SiCl₄ with R₂PO(OH) (R=Me, Cl) yield compounds with six-fold coordinated silicon atoms. Whereas R=Me afforded the hexacoordinated tetra-cationic silicon complex [Si(Me₂PO(OH))₆]⁴⁺ with chloride counter-ions, R=Cl caused release of HCl with formation of a cyclic dimeric silicon complex [Si(Cl₂PO(OH))(Cl₂PO₂)₃(μ-Cl₂PO₂)]₂ with bridging bidentate dichlorophosphates.     

Syntheses,Structures, and Reactivities of Sulfur-Containing Cycloalkenes

Sulfur-containing cycloalkenes possessing disulfide units 1, 2, and 3 were obtained by oxidation of cis-disodium ethene-1,2-dithiolate, and their crystal structures were determined by the X-ray crystallographic analyses. Compound 1 was found to give the ring expansion product 3 in acetonitrile even at room temperature and also form reactive thioaldehyde under irradiation.     

Spectroscopy and crystal structure of anabasine salts

The anabasinium hydrochloride, hydriodide and perchlorate were characterized by IR and NMR spectroscopy as well as by X-ray diffraction. Anabasinium hydrochloride crystallizes with three independent ionic pairs in the asymmetric part of the orthorhombic unit cell, while anabasinium hydriodide and perchlorate crystals, being isostructural, are hexagonal and contain only one symmetry independent ionic pair. Despite these differences in the crystal data, both types of crystals display very similar helical solid-state patterns. The reported results combined with the CSD searches indicate an inherent tendency of anabasinium salts to crystallize with multiple asymmetric units, and to form folded arrangements in crystals. In the solid state the anabasinium cations predominantly adopt either synperiplanar or antiperiplanar conformations with respect to the mutual orientation of C^*–H and pyridine C–C(N) bonds, with deformations towards, respectively, (+) synclinal or (+) anticlinal rotamers.     

ELECTRON-RICH THIAZENES: SOME PRINCIPLES OF SYNTHESIS AND STRUCTURE

Abstract

General methods of preparation and typical bond distances and bond angles (at sulfur and nitrogen) are reviewed for cyclic sulfur–nitrogen compounds. Correlations between sulfur-nitrogen bond distance and unstrained bond angles in SNS and NSN groups can be used to assess angular strain in 4 and 5 atom thiazene rings and the optimum ring geometries of larger thiazene cations such as S₅N⁺ ₅ and S₄N_{2+ 4}. The geometry of S₃N^? ₃ is also discussed.     

The Synthesis and Characterization of a New Layered Chlorozincophosphate Zn(HPO4)Cl[C4H10N]

Along a systematic study of open-framework materials aiming at producing new molecular sieves, we characterized a new zincophosphate Zn(HPO₄)Cl[C₄H₁₀N]. It was synthesized under mild conditions (r.t.) in the presence of pyrrolidinium as an organic-structure directing agent. The structure of this compound, determinated by single crystal X-ray diffraction, consists of anionic parallel [Zn(HPO₄)Cl]^? sheets alternating with thick slabs of organic molecules (C₄H₁₀N)⁺. These latters are linked to the anionic sheets through hydrogen bonds. Zn(HPO₄)Cl[C₄H₁₀N] crystallizes in the monoclinic system and the space group C2/c (No. 9) with cell parameters a = 24,83(9), b = 9,258(5), c = 8.778(3), β = 110,45(4), Z = 8, V = 1891.0(14) Åt³, R = 0.045, and R_w = 0.07. Solid state ³¹P and ¹³C MAS NMR spectroscopies are in agreement with the X-ray structure.     

Supramolecular interactions in high molecular weight bisdithiocarbamate adducts of divalent Zn(II), Cd(II), and Hg(II): spectral,VBS, and single crystal X-ray structural studies on MS4N2 chromophores

This article describes supramolecular interactions induced in a high molecular weight dithiocarbamate, padtc, by its design. Synthesis, spectral studies involving zinc, cadmium and mercury, padtc, and adducts with tmed, such as [Zn(padtc)₂] (1), [Zn(padtc)₂(tmed)]?·?C₆H₅CH_3?·?0.5(H₂O) (2), [Cd(padtc)₂] (3), [Cd(padtc)₂(tmed)]?·?C₆H₅CH₃?·?0.36(H₂O) (4), [Hg(padtc)₂]?·?H₂O (5), [Hg(padtc)₂(2,2′-bipy)]?·?H₂O (6), [Hg(padtc)₂(1,10-phen)]?·?H₂O (7), and [Hg(padtc)₂(oxine)]?·?H₂O (8) (where padtc^??=?N,N′-(iminodiethylene)bisphthalimidedithiocarbamate, 1,10-phen?=?1,10-phenanthroline, tmed?=?tetramethylethylenediamine, 2,2′-bipy?=?2,2′-bipyridine, oxine?=?8-hydroxyquinoline) along with the single crystal X-ray structural analysis of [Zn(padtc)₂(tmed)]?·?C₆H₅CH₃?·?0.5(H₂O) (2) and [Cd(padtc)₂(tmed)]?·?C₆H₅CH₃?·?0.36(H₂O) (4) are reported. All the complexes were characterized by IR, NMR (¹H and ¹³C), and thermogravimetric study. The IR spectra of the complexes show the contribution of the thioureide form to the structures. In ¹³C NMR spectra, the most important thioureide (N¹³CS₂) carbon signals are observed at 210–212?ppm. Single crystal X-ray structural analyses of 2 and 4 show the presence of extensive supramolecular interactions stabilizing the solid-state structure. Both zinc and cadmium are in a distorted octahedral environment with MS₄N₂ chromophores. VBS of Zn and Cd are 1.76 and 1.98, respectively, supporting the correctness of the determined structure and the valence of the central metal ions.     

A minimalist NMR approach for the structural revision of mucoxin

In an attempt to revise the structural assignment of mucoxin, and faced with 64 diastereomeric possibilities, we resorted to the synthesis of truncated structures that contained the core stereochemical sites. Twelve stereochemical analogues were synthesized, their (1)H and (13)C NMR spectra were analyzed and four recurring stereochemical trends were distilled from the data. Applying the observed trends to the diastereomeric population pared the possible choices for the correct structure of mucoxin from 64 to 4. Synthesis of these analogues led to the identification of the correct structure of mucoxin.     

The Structure of New Host Molecules that form Channel Inclusion Compounds

1,3-Benzenediamine,N,N′-bis(4,6-dichloro-1,3,5-triazine-2-yl) and 1,3,5-Triazine,2,2′-[2-methyl-1,3-phenylenebis(oxy)] bis(4,6-dichloro) were synthesized as host molecules. The inclusion compound of 1,3-Benzenediamine,N,N′-bis(4,6-dichloro-1,3,5-triazine-2-yl) crystallizes in the monoclinic crystal system in space group C2/c. The host molecule occupies the space group 2-fold special position and packed in the crystal lattice in such a manner as to leave channels running along the c axis of a rectangular cross-section. It crystallizes with two molecules of acetone that are hydrogen bonded to the amino nitrogen atoms. Molecules of 1,3,5-Triazine,2,2′-[2-methyl-1,3-phenylene bis(oxy)]bis(4,6-dichloro) are packed in the crystal in such a manner as to leave channels of a trapezoid cross-section that are running along the a axis. Guest molecules such as metanol, ethanol, and ethyl acetate can be used to fill the channels. The crystal structures of two inclusion compounds are described.