Monohalogenated ferrocenes C5H5FeC5H4X (X = Cl,Br and I) and a second polymorph of C5H5FeC5H4I

The structures of the three title monosubstituted ferrocenes, namely 1‐chloroferrocene, [Fe(C₅H₅)(C₅H₄Cl)], (I), 1‐bromoferrocene, [Fe(C₅H₅)(C₅H₄Br)], (II), and 1‐iodoferrocene, [Fe(C₅H₅)(C₅H₄I)], (III), were determined at 100 K. The chloro‐ and bromoferrocenes are isomorphous crystals. The new triclinic polymorph [space group P, Z = 4, T = 100 K, V = 943.8 (4) ų] of iodoferrocene, (III), and the previously reported monoclinic polymorph of (III) [Laus, Wurst & Schottenberger (2005). Z. Kristallogr. New Cryst. Struct. 220 , 229–230; space group Pc, Z = 4, T = 100 K, V = 924.9 ų] were obtained by crystallization from ethanolic solutions at 253 and 303 K, respectively. All four phases contain two independent molecules in the unit cell. The relative orientations of the cyclopentadienyl (Cp) rings are eclipsed and staggered in the independent molecules of (I) and (II), while (III) demonstrates only an eclipsed conformation. The triclinic and monoclinic polymorphs of (III) contain nonbonded intermolecular I...I contacts, causing different packing modes. In the triclinic form of (III), the molecules are arranged in zigzag tetramers, while in the monoclinic form the molecules are arranged in zigzag chains along the a axis. Crystallographic data for (III), along with the computed lattice energies of the two polymorphs, suggest that the monoclinic form is more stable.     

In search for a pentacoordinated monoorgano stannyl cation

Alkylation of Sn(OCH₂CH₂NMe₂)₂ (1) by MeI or MeOTf leads to a mixture of quaternary ammonium salts by alkylation of the NMe₂ moiety. Reaction of Sn(acac)₂ (2) with MeOTf gives unexpected redistribution product Sn(acac)OTf (3), which is a rare example of mono acetylacetonato tin (II) derivatives. Pentacoordinated monoorgano stannyl cation was generated by salt metathesis from PhSn(OCH₂CH₂NMe₂)₂Cl (5) and Ag[Al(OCH(CF₃)₂)₄] or Ag[B(C₆F₅)₄]. This cation was not isolated due to its strong electrophilic nature. It abstracts substituents from aluminate and borate weakly coordinating anions (WCAs) leading to redistribution products [Al[OCH(CF₃)₂]₂OCH₂CH₂NMe₂]₂ (6) and [Ph(C₆F₅)Sn(OCH₂CH₂NMe₂)₂][H₂OB(C₆F₅)₃] (9), respectively. Structures of 3 and 6 were established by single-crystal X-ray diffraction analysis.     

Crystal and molecular structures of three germylated steroids

Germylated steroids were studied by X-ray diffraction analysis for the first time. The conformational parameters of the molecules in the crystals are discussed. The three-center hypervalent O−Ge−Cl bonds are observed in two β-isomers. The geometric parameters of the hypervalent units are compared. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 116–122, January, 1999.     

Heterocyclization of cycloalkenes with di(2-pyridyl) diselenide in the presence of antimony pentachloride

Cycloalkenes react with di(2-pyridyl) diselenide in the presence of antimony pentachloride with the formation of products of the selenenylating electrophile cycloaddition at the multiple bond. The final products of heterocyclization, chloroantimonates(III) of 2,3-dihydro[1,3]selenazolo[3,2-a]pyridinium derivatives were isolated.     

Crystal structure of ethyl 9-methyl-10-phenyl-11-thioxo-8-oxa-10,12-diazatricyclo[7.3.1.02.7] trideca-2(7),3,5-trien-13-carboxylate

Three-component condensation of N1-phenylthiocarbamide with salicylaldehyde and with the ether of acetoacetic acid in the presence of trifluoroacetic acid provides a productive synthesis of ethyl 9-methyl-10-phenyl-1 1-thioxo-8-oxa-10,12-diazatricyclo[7.3.1.0^2.7]trideca-2(7),3,5-trien-13-carboxylate I. Single crystal XRD is used to determine the crystal structure of I and to identify the conformation properties of the structures.     

The easy hydrolysis of hexacyanocyclopropane, ethyl 1,2,2,3,3-pentacyanocyclopropane-1-carboxylate, 1,2,2,3,3-pentacyanocyclopropane-1-carboxamide, andN,N-dimethyl-1,2,2,3,3-pentacyanocyclopropane-1-carboxamide tor-1,c-2,c-3-tricyanocyclopropane-t-carboxamide

Hydrolysis of hexacyanocyclopropane (1a), ethyl 1,2,2,3,3-pentacyanocyclopropane-1-carboxylate (1b), 1,2,2,3,3-pentacyanocylopropane-1-carboxamide (1c), andN,N-dimethyl-1,2,2,3,3-pentacyanocylopropane-1-carboxamide (1d) in 95% acetic acid yieldsr-1,c-2,c-3-tricyanocyclopropane-t-1-carboxamide (3). The structure of3 was proved by X-ray diffraction analysis. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 454–456, March, 1998.     

Synthesis and X-ray structural study of 1-adamantylmethyl 2-cyanoacrylate and 1,10-decanediol bis-2-cyanoacrylate

I-Adamantylmethyl 2-cyanoacrylate (1) was prepared by the reaction of 2-cyanoacryloyl chloride with 1-adamantylmethanol . 1,10-Decanediol bis-2-cyanoacrylate (2) was synthesized by transesterification of methyl 2-cyanoacrylate with 1,10-decanediol. Esters1 and2 were studied by X-ray structural analysis.Deceased in 1995.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2288–2292, September, 1996.