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X-Ray Structure Determinations of Bromo- and/or Bromomethyl-substituted Benzenes: C-H center dot center dot center dot Br, C-Br center dot center dot center dot Br, and C-Br center dot center dot center dot pi Interactions
No full textZ. Naturforsch. 2012, 67b, 1273-1281 / DOI: 10.5560/ZNB.2012-0249 Received September 18, 2012 Belatedly dedicated to Professor Joachim Heinicke on the occasion of his 65th birthday The structures of seven benzene derivatives [1,2,3-tri(bromomethyl)benzene, (1); 3,5-di(bromomethyl)bromobenzene, (2); 2,5-di(bromomethyl)bromobenzene, (3); 4-(bromomethyl)-2,5-dibromotoluene, (4); 4-(bromomethyl)bromobenzene, (5); 2,3-di(bromomethyl)bromobenzene, (6) and (bromomethyl)-p-dibromobenzene, (7)] with bromo and bromomethyl (and in one case methyl) substituents are presented and analysed in terms of Br center dot center dot center dot Br interactions up to 4.0 angstrom, supported by hydrogen bonds H center dot center dot center dot Br. Some interactions of the type Br center dot center dot center dot pi and pi center dot center dot center dot pi are encountered and play a subordinate role in the packing. Despite the close chemical similarity of the compounds, some of which are isomers with permuted substituent positions, the packing motifs are highly variable. Compounds 2-5 are based on layer structures with Br-n (n = 3, 4) and/or mixed Br/C rings. Compounds 1, 6 and 7 display three-dimensional packings of differing complexity, but with interpretable substructures; 1 can be analysed in terms of ribbons of linked Br-3 and Br-4 rings; 6 displays chains of linked Br-3 triangles; 7 consists of ribbons of linked Br-4 quadrilaterals
4-Iodo-1,3,5,7-tetramethyl-1,3,5,7-tetraaza-45-phosphaspiro[3.3]heptane-2,6-dione: Synthesis and Crystal Structure of the First Iodophosphorane
No full textThree Crystal Structures of Terephthalic Acid Salts of Simple Amines
No full textDiphenethylamine forms two adducts (1 : 1, la and 2 : 1, 1b) with terephthalic acid (H(2)TPA). The former is bis(diphenethylammonium)H-2 TPA center dot TPA(2-) and the latter is bis(diphenethylammonium)center dot TPA(2-). The amine cis-2,6-dimethylpiperidine forms a hydrated 2 : 1 adduct, bis(2,6-dimethylpiperidinium)center dot TPA(2-)center dot H2O (2). The crystal structures of all three compounds were determined. All H(2)TPA and TPA(2-) residues display inversion symmetry, while the water oxygen atom of 2 lies on a twofold axis. Packing analyses have identified some supramolecular synthons known from related structures
Gold(I) complexes with amine ligands, 6 - Hydrogen bonding networks in bis(amine)gold(I) complexes with disulfonylamide anions
No full textThe use of disulfonylamines as counter-ions allows the synthesis of stable ionic gold(I) complexes with the amine ligands cyclohexylamine, benzylamine, 3-iodobenzylamine, morpholine, pyrrolidine, and piperidine. There is a considerable increase in stability for the morpholine complex compared to the previously synthesised chloro derivative; the benzylamine derivatives displayed better solubility and crystallinity than their chloro analogues. The use of silver disulfonylamine derivatives in the syntheses led in two cases to the incorporation of silver into the products, with concomitantly poor yields. Crystal structure determinations of eight complexes revealed, as expected, extensive systems of N-H ... O hydrogen bonds. Amines with NH functions tend to form hydrogen-bonded chain motifs, those with NH, as donor group form layers of linked ring patterns. It thus seems that the packing can more easily be classified in terms of influence of the cation than of the anion. Some C-H O hydrogen bonds were also observed, but play a less important role. Aurophilic contacts were not observed, although one mixed gold/silver complex displayed short Au Ag contacts. Of the two compounds containing iodine, only one showed short I I contacts
Preparation of the hydrocarbon-soluble trifluoro complex LTiF3 with a beta-diketiminato ligand
No full textThe beta-diketiminato fluoride complex (LTiF3) (1) (L = HC(CMeN(2,6-iPr(2)C(6)H(3)))(2), "NacNac") has been obtained using two synthetic routes, interaction of TiF4 and NacNacK center dot 2THF in toluene and interaction of LTiCl3 and 3 equiv. of Me3SnF in toluene. The trifluoro complex (LTiF3) (1) is soluble in the non-polar solvents toluene and hexane and moderately active in polymerization of ethylene; the activity is higher than that of LTiMe3 and comparable with that of the oxo-bridged complexes LTiCl(mu-O)(2) TiClL and LTiMe(mu-O)(2)TiMeL.toluene. Compound 1 was characterized by single crystal X-ray structural analysis, elemental analysis, NMR spectroscopy, and mass spectrometry. Complex 1 in the solid state is a centrosymmetric dimer containing two LTiF2 moieties connected by two bridging fluorines, whereas C6D6 and CD3CN solutions of 1 contain the monomeric complex at room temperature. (c) 2008 Elsevier B.V. All rights reserved
Gold(I) complexes with amine ligands, 6 - Hydrogen bonding networks in bis(amine)gold(I) complexes with disulfonylamide anions
No full textThe use of disulfonylamines as counter-ions allows the synthesis of stable ionic gold(I) complexes with the amine ligands cyclohexylamine, benzylamine, 3-iodobenzylamine, morpholine, pyrrolidine, and piperidine. There is a considerable increase in stability for the morpholine complex compared to the previously synthesised chloro derivative; the benzylamine derivatives displayed better solubility and crystallinity than their chloro analogues. The use of silver disulfonylamine derivatives in the syntheses led in two cases to the incorporation of silver into the products, with concomitantly poor yields. Crystal structure determinations of eight complexes revealed, as expected, extensive systems of N-H ... O hydrogen bonds. Amines with NH functions tend to form hydrogen-bonded chain motifs, those with NH, as donor group form layers of linked ring patterns. It thus seems that the packing can more easily be classified in terms of influence of the cation than of the anion. Some C-H O hydrogen bonds were also observed, but play a less important role. Aurophilic contacts were not observed, although one mixed gold/silver complex displayed short Au Ag contacts. Of the two compounds containing iodine, only one showed short I I contacts
Diazadioxacyclophanes
No full textSix new cyclophane molecules (5-10) were synthesized from alpha,alpha'-bis(N-tosyl-4-aminophenyl)-1,4-diisopropylbenzene and alpha,alpha'-bis[4-(n-bromoalkyloxy)phenyl]-1,4-diisopropylbenzene. The crystal and molecular structures of alpha,alpha'-bis(4-aminophenyl)-1,4-diisopropylbenzene (3), alpha,alpha'-bis (N-tosyl-4-aminophenyl)-1,4-diisopropylbenzene 4 and the ditosyl derivative of the diazadioxacyclophane 6 were determined. The noncyclic compounds 3 and 4 display the ami conformation. Diazadioxacyclophane 6 possesses a central cavity that might be exploited to accommodate guest molecules, but some conformational change would probably be required.The Welch Foundation [Grant D-0775
Intramolecular Formal anti-Carbopalladation/Heck Reaction: Facile Domino Access to Carbo- and Heterooligocyclic Dienes
No full textAn intramolecular domino process consisting of a formal anti-carbopalladation followed by Heck reaction is realized. Complex oligo(hetero)cyclic scaffolds are efficiently obtained in one synthetic step from easily obtainable enyne precursors. In contrast to common syn-carbopalladation reactions of alkyne units, the carbopalladation employed here is designed to afford an anti-arrangement of the two new substituents across the emerging double bond. A prerequisite is that the residues next to the alkyne should lack any beta-hydrogen atoms. The method paves the way to tri- and tetrasubstituted double-bond systems that have not been accessible by conventional Pd catalysis
Secondary interactions in n-(chloromethyl)pyridinium chlorides (n=2, 3, 4)
No full textIn the isomeric title compounds, viz. 2-, 3- and 4-(chloromethyl)pyridinium chloride, C6H7ClN+.Cl-, the secondary interactions have been established as follows. Classical N-H...Cl- hydrogen bonds are observed in the 2- and 3-isomers, whereas the 4-isomer forms inversion-symmetric N-H(...Cl-...)(2)H-N dimers involving three-centre hydrogen bonds. Short Cl...Cl contacts are formed in both the 2-isomer (C-Cl...Cl-, approximately linear at the central Cl) and the 4-isomer (C-Cl...Cl-C, angles at Cl of ca 75degrees). Additionally, each compound displays contacts of the form C-H...Cl, mainly to the Cl- anion. The net effect is to create either a layer structure (3-isomer) or a three-dimensional packing with easily identifiable layer substructures (2- and 4-isomers)
Unexpected Side Products in the Large-Scale Preparation of 2,3-Dihydro-1,1,2,2,3,3-hexamethyl-1H-indene
No full textAbstract During the development of an optimized procedure for the synthesis of 2,3-dihydro-1,1,2,2,3,3-hexamethyl-1H-indene significant amounts of 5-tert-butyl-2,3-dihydro-1,1,2,2,3,3-hexamethyl-1H-indene were formed, along with 5-tert-hexyl-2,3-dihydro-1,1,2,2,3,3-hexamethyl-1H-indene under certain conditions. The structures of 5-tert-hexyl-2,3-dihydro-1,1,2,2,3,3-hexamethyl-1H-indene and 5-tert-butyl-2,3-dihydro-1,1,2,2,3,3-hexamethyl-1H-indene were established by spectroscopic means and confirmed by X-ray single-crystal structure determinations. The mechanism for the formation of 5-tert-butyl-2,3-dihydro-1,1,2,2,3,3-hexamethyl-1H-indene is discussed
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