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Tri(p-tolyl)antimony dichloride was prepared by oxidation of tri(p-tolyl)stibine with chlorine or copper(II) chloride. As found by X-ray diffraction analysis, the antimony atom in tri(p-tolyl)antimony dichloride has the configuration of trigonal bipyramid with axially located chlorine atoms. The Sb-Cl and Sb-C distances are 2.476(2) and 2.104(7) A, and the CSbC and ClSbCl angles are 120 and 180°, respectively.

The complexes [Cd(H2O)6](C5HN2O6)2 · 2H2O (I) and [Co(H2O)6](C5HN2O6)2 · 2H2O (II) were obtained in the crystalline state by reactions of cobalt chloride and cadmium chloride with ammonium 4-nitro-2,3,5,6-tetraoxopyridinate, (NH4)2 · (C5HO6N2)2. Their cocrystallization gave the heterometallic complex [Cd0.32Co0.68(H2O)6](C5HN2O6)2 · 2H2O (III). The crystal and molecular structures of complexes I-III were determined by X-ray diffraction. It was demonstrated that the complexation reactions occur by replacement of two ammonium cations 4-nitro-2,3,5,6-tetraoxopyridinate by the complex cations [M(H2O)6]2+. The tetraoxopyridinate anions and the complex cations are hydrogen-bonded through the coordinated and crystallization water molecules as well as through the O atoms of the organic anion. The thermolysis of complexes I and II was examined by TGA.

The oxidative nitration of 2-amino-3-hydroxypyridine in the presence of rare-earth metal cations allocates 2-ethoxy-3-hydroxy-4,6-dinitropyridine (I) as one of the reaction products. Treating compound I with a sodium hydroxide solution gives diaquasodium bis(2-ethoxy-3-hydroxy-4,6-dinitropyridinate) (II). The molecular and crystal structures of I and II were studied. The compounds were characterized by spectroscopic methods (IR and electronic absorption spectroscopy). The acidic dissociation constant of compound I was evaluated.

The crystal and molecular structures of bis(2-methylimidazolium) tetrabromocuprate(II) are determined. The linear dependences of the degree of distortion of the CuBr 4 2− coordination polyhedron on the protonation constant of the organic cation are revealed for the structures with θ < 140°. The dependence of the hydrogen bond parameters (distances H…Br and N…Br, angle NHBr) on the degree of distortion of CuBr 4 2− is shown. The degree of distortion of CuX 4 2− (X = Cl, Br) is determined by the type of the organic cation and is almost the same for the CuBr 4 2− and CuCl 4 2− polyhedra. The empirical equations relating the degree of distortion of CuX 4 2− (X = Cl, Br) and the position of the Cu ← X ligand-to-metal charge-transfer band (νLMCT) are obtained.

The reaction of (pentafluorophenyl)diphenylphosphine with C-ethoxycarbonyl-(p-methoxyphenyl) nitrile imine was used to synthesize [2,3,4,5-tetrafluoro-6-(p-methoxyphenylamino)phenyl]diphenylphosphine oxide whose reduction with trichlorosilane gave [2,3,4,5-tetrafluoro-6-(p-methoxyphenylamino)phenyl] diphenylphosphine, the first representative of tertiary ortho-arylamino-substituted arylphosphines. According to X-ray diffraction data, the principal steric characteristics of the phosphine are close to those known for triarylphosphines.

Mercury 7-amylthio-8-mercaptoquinolinate Hg[C9H5(SC5H11)NS]2 has been synthesized and studied by X-ray diffraction. The crystals are triclinic: a = 8.980(2) A, b = 9.298(2) A, c = 18.909(4) A, α = 93.66(2)°, β = 98.00(2)°, γ = 62.25(2)°, V = 1383.7(5) A3, ρcalcd = 1.74 g/cm3, Z = 2, space group P1. The structure is formed by neutral asymmetric complexes in which two 7-amylthio-8-mercaptoquinoline ligands coordinate, in a bidentate fashion (N,S), a mercury atom (Hg-S, 2.363(2) and 2.376(2) A; Hg-N, 2.436(6) and 2.466(7) A). The coordination polyhedron of mercury, which is a “swing” (2S+2N), has an SHgS bond angle equal to 173.5(1)°. Some structural features of the ligands in mercury, zinc and copper 7-amylthio-8-mercaptoquinolinates are discussed.

Reactions of 4-methyl-1,3-thiazole-2(3H)-thiones with various C,N-disubstituted nitrile imines occurred by the common [3+2]-cycloaddition scheme leading to the formation in general of stable spiro compounds. In reactions of o-nitrophenylnitrile imines acyclic compounds were the main products.

Two- and three-component condensations of paraformaldehyde with trifluoromethanesulfonamide, acetamide, trifluoroacetamide, 1H-benzotriazole, methanesulfonamide, and malonamide were studied. N-Hydroxymethyl derivatives of trifluoroacetamide and 1H-benzotriazole reacted with trifluoromethanesulfonamide to give N-(trifluoroacetylaminomethyl)- and N-(1H-benzotriazol-1-ylmethyl)-substituted derivatives of tri-fluoromethanesulfonamide, as well as N,N′-methylenebis(trifluoromethylsulfonamide) and N-(trifluoromethyl-sulfonylaminomethyl)trifluoroacetamide as transamination products. Three-component condensation of trifluoromethanesulfonamide with paraformaldehyde and methanesulfonamide led to the formation of 1-methylsulfonyl-3,5-bis(trifluoromethylsulfonyl)hexahydro-1,3,5-triazine, and the reaction of trifluoromethanesulfonamide with paraformaldehyde and malonamide gave 4,10-bis(trifluoromethylsulfonyl)-2,4,8,10-tetraazaspiro-[5.5]undecane-1,7-dione whose structure was proved by X-ray analysis.

The formation mechanism of the active catalyst in the oxidative carbonylation of terminal alkynes at the ≡C-H bond has been investigated for the catalytic system Pd(OAc)2-PPh3-p-benzoquinone (Q)-MeOH. It has been demonstrated by NMR spectroscopy, X-ray crystallography, and kinetic measurements that the catalytically active palladium is in the oxidation state 0 and is bound into complexes stabilized by p-benzoquinone (PdL2Q, where L = PPh3). A mechanism is suggested for the catalytic process, which includes the formation of the complex PdL2Q, the oxidative addition of the alkyne to this complex at the ≡C-H bond, the insertion of CO into the Pd-C bond, and steps in which hydride hydrogen is intramolecularly transferred to the p-quinone.

The ratio between adducts III and IV varies in a wide range depending on reaction conditions. The ratio between adducts III and IV isolated from the reaction mixture obtained by reacting hexaethyltriamidophosphite with SO 3 at –75 ° C in methylene chloride is close to 1 : 3. Vacuum pyrolysis of the adducts at 160 ° C results in triamidophosphate V and sulfur dioxide in 73% yield. Hexaethyltriamidophosphite reacts with SO 3 preliminarily bound to pyridine (as pyridine–sulfur trioxide) to give adduct IV in quantitative yield. The concurrent formation of two kinds of adducts was proved by the treatment of the resulting products with antimony pentachloride in methylene chloride at –40 ° C to produce donor–acceptor complexes VI and VII . Antimony pentachloride as a strong Lewis acid displaces sulfur dioxide from adduct III and sulfur trioxide from adduct IV to yield complexes VI and VII , respectively

The transformations of platinum(II) and platinum(IV) complexes with inner-and outer-sphere ligands by the action of (+)-α-pinene and (+)-limonene were studied. Reduction of the metal complex is the main process whose rate increases in the following outer-sphere ligand series: (Me2SO)2H+ < Et3NH+ < K− < H+. The reaction of K2PtCl4 with α-pinene gave cis-terpine monohydrate and dichloro-η4-[p-mentha-1,8(9)-diene]platinum(II), and their structure was proved by X-ray analysis. The complex belongs to monoclinic crystal system, the Pt-Cl and Pt-C bonds therein have different lengths, the ClPtCl angle is 85.88°, and the C=C bond plane is orthogonal to the square coordination core. Dichloro-η4-[p-mentha-1,8(9)-diene]-platinum(II) was tested as catalyst in the hydrosilylation of acetophenone with diphenylsilane.

The gadolinium nitrato complex with α-furancarboxylic acid (FA) and 2,2′-dipyridyl (Dipy) has been synthesized. According to X-ray diffraction results, the complex is composed of the [Gd(FA)2(NO3)(Dipy)]2 dimers. The crystals are triclinic: a = 9.942(2) A, b = 10.231(2) A, c = 11.037(2) A, α = 85.50(3)°, β = 75.71(3)°, γ = 69.82(3)°, Z = 1. Two gadolinium atoms are linked by four carboxylate groups of furancarboxylic acid molecules. Each gadolinium atom is coordinated to seven oxygen atoms (five belonging to the FA carboxyl groups and two belonging to the bidentate nitrate group) and to two nitrogen atoms (from Dipy).

Mercury 8-selenolquinolinate was synthesized and studied by X-ray diffraction. In neutral Hg(C9H6NSe)2, 8-selenolquinoline is a bidentate (S,N) ligand. The coordination polyhedron of mercury is a distorted tetrahedron or a seesaw (2Se + 2N). The bond lengths are as follows: Hg-Se, 2.4599(9) and 2.4606(9) A; Hg...N, 2.497(6) and 2.513(6) A. The SeHgSe bond angle is 166.07(3)°. Mercury 8-selenolquinolinate belongs to the class of chelates in which the five-membered chelate rings-Hg-Se-C-C-N-contain a donor selenium atom. The structures and the Hg-Se, Hg-S, Hg-O, and Hg-N bonds in mercury 8-selenol-, 8-mercapto-, and 8-hydroxyquinolinates were analyzed.

Reactions of thiazoline-2-thione with C,N-disubstituted nitrile imines were investigated. The reaction products are substituted 2-(1,3,4-thiadiazol-2-ylideneamino)ethanethiols and bis[2-(1,3,4-thiadiazol-2-ylideneamino)ethyl] disulfides. The reaction of thiazoline-2-thione with a double excess of nitrile imine did not considerably change the process route. The structure of compounds obtained was proved by X-ray diffraction analysis. A presumable scheme is given describing the formation of compounds obtained.

2,3,3-Triphenyl-1-thioxophthalimidine reacted with nitrile imines along the pattern of [3+2]-cycloaddition affording 2,3,3,3′,5′-pentasubstituted benzo[c]pyrrolidine-1-spiro-2′-(2′,3′-dihydro-1′,3′,4′-thiadiazoles). The reaction is regioselective and involves the exocyclic C=S bond.

Acid anilinium dodecatungstenphosphate of composition (C6H5NH3)2H[PW12O40] ⋅ 2H2O is synthesized and characterized by X-ray diffraction analysis, IR spectroscopy, and thermogravimetry. The crystals are monoclinic: space group P21/m, a = 9.940(2) A, b = 15.412(3) A, c = 16.201(3) A, β = 100.42(3)°, Z = 2, ρcalcd = 4.221 g/cm3. The structure contains heteropolyanions [PW12O40]3−, cations [C6H5NH3]+ and H+, and molecules of water of crystallization. The heteropolyanions and anilinium cations in crystal are linked by the electrostatic interaction and hydrogen bonds.

4-Aryl-2-phenyl-1,2-dihydrophthalazine-1-thiones react with nitrile imides according to the [3 + 2]-cycloaddition pattern to give phthalazinespirothiadiazoles. The reaction occurs regioselectively at the exocyclic C=S bond.

The reaction of 3-phenyl-2-phenylethynyl-1,3,2λ3-oxazaphospholidine with nitrilimines is a multistep process involving formation of the diazaphosphorine ring and cleavage of the oxazaphospholidine ring. The final products are the substituted 4-[N-phenyl-N-(2-chloroethyl)amino]-1,4-dihydro-1,2,4λ5-diazaphosphorines. According to X-ray structural data obtained for 4-[N-phenyl-N-(2-chloroethyl)amino]-1,4-dihydro- 1,5-diphenyl-3-ethoxycarbonyl-1,2,4λ5-diazaphosphorine, the heteroring of these compounds has the conformation of a flattened P-envelope.

Main products of reaction between benzothiazole-2-thione and a double excess of nitrilimine are substituted 1-aryl-1-(1,3-benzothiazol-2-yl)-2-(2,3-dihydro-1,3,4-thiadiazol-2-yl)hydrazines. In the first step presumably forms a spiro compound via 1,3-dipolar cycloaddition of nitrilimine molecule to the C=S bond of the benzothiazolethione. The second nitrilimine molecule adds to the new C=S bond of the intermediate product arising by the rupture of CS bond in the thiadiazole ring of the spiro compound.

Benzothiazole-2-thione reacted with C,N-disubstituted nitrilimines to give the corresponding bis-[2-(1,3,4-thiadiazol-2-ylideneamino)phenyl] disulfides. In some cases, α-(1,3-benzothiazol-2-ylsulfanyl)-(α-R)-alkanone arylhydrazones were formed as by-products. The structure of the isolated compounds was proved by X-ray analysis.

Peculiar phosphacyclophanes were prepared from symmetrical 2,6- and unsymmetrical 1,6-dihydroxynaphthalenes. The position of the hydroxy groups in dihydroxynaphthalenes considerably affects their reactivity, the structure of the phosphacyclophanes obtained, and also the disproportionation of bisphosphoramidites. Oxo and thio derivatives of these phosphoramidites as well as their molybdenum complexes were prepared.

Cyclobisphosphorylation of dihydroxynaphthalenes was studied with the aim to prepare organo- phosphorus aromatic compounds containing intramolecular cavities. The design and the structural and chemical features of cyclobisphosphites prepared from unsymmetrical 1,7-dihydroxynaphthalene are con- sidered. New data are reported on regioselective cyclophosphorylation of 1,7-dihydroxynaphthalene by dis- proportionation of its bis(diamidophosphorylated) derivatives.

A number of bis-phosphorylated 1,4:3,6-dianhydro-D-mannitol derivatives were synthesized. The increased steric loading of the phosphorus-containing residues in the compounds prepared gives rise to complicated 1H and 31P NMR spectra and magnetic nonequivalence of structurally similar molecular fragments.

Methionine sulfone , a product of complete oxidation of sulfur in methionine amino acid, was subjectedto X-ray diffraction study on a single crystal. According to X-ray diffraction data the packing of methioninesulfone molecules in a crystal is characteristically strongly anisotropic and it is stabilized by a network of intermolecularhydrogen bonds.

Crystal structure of 2,3-dihydroxypyridine (H2L) is determined. Mn(HL)Cl · H2O, Co(HL)Cl · 2H2O, Cu(HL)Cl, Ni(HL)OH · H2O, and Zn(HL)OH · H2O complexes are synthesized by reacting Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) chlorides with H2L in ethanol solutions and identified. In these complexes, 2,3-dihydroxypyridine is involved in coordination as a monoanion. Spectral parameters of neutral and anionic forms of a ligand are determined and the acidity and complex formation constants are calculated. The compositions of complexes are established.

According to X-ray diffraction data, the nickel complex [Ni(Bu3P)2(NCS)2] has a square-planar structure with the two phosphine ligands trans to each other and the thiocyanate ligand coordinated by the nitrogen atom. The IR and 1H, 13C, and 31P NMR data show that the same structure is preserved in solutions. The catalytic activity of the complex in hydrosilylation of 1-hexene with chlorohydrosilanes HSiMe3-nCln varies in the series HSiCl3 > HSiMeCl2 > HSiMe2Cl. The reactions of the complex with hydrosilanes involve substitution of the anionic ligand and formation of silyl complexes.

The results of X-ray structure investigations of crystalline compounds with a tricyanovinyl group (individual substances, molecular complexes, and ionic salts) and related compounds are generalized. The most interesting geometric and conformational characteristics of the molecules and ions are discussed. Consideration is given to the crystal chemical features of the compounds involved. The structural formulas of 73 compounds and the reliability factors (R factors) of crystal structure determination are given in the tables.

Chiral diamines having a C2 symmetry, (4S,5S)-2,2-dimethyl-4,5-bis(aminomethyl)-1,3-dioxolane and (5S,5'S)-2,2,2',2'-tetramethyl-3,3'-diphenyl-5,5'-bioxazolidine, were synthesized on the basis of (+)-(2R,3R)-tartaric acid. Their structure was proved by X-ray analysis. The products were used as ligands in rhodium catalyst for enantioselective hydrogenation of α-acetamidocinnamic and itaconic acids.

Tritylation of tetrazole and its 5-substituted derivatives with triphenylmethyl chloride under conditions of phase-transfer catalysis regioselectively yields the corresponding 5-substituted 2-trityltetrazoles which can be used to protect NAH bonds in nitrogen-containing heterocycles and OAH bonds in primary alcohols. Thermolysis of 2-trityltetrazoles in benzonitrile leads to 3,6-disubstituted 1,2,4,5-tetrazines. Thermal transformation of the same compounds in dodecane follows a radically different mechanism, resulting in formation of difficultly accessible 8,8-diphenylheptafulvenes. The structure of the latter was proved by X-ray analysis.

The complex compounds [Co(DH)2(Anil)2][BF4] and [Co(DH)2(Py)2][BF4] were synthesized from Co(BF4)2 · 6H2O–DH2–A–alcohol–water systems (DH2 is dimethylglyoxim and A is pyridine (Py) or aniline (Anil)), and their crystal structures were determined using X-ray diffraction analysis. In octahedral Co(III) complexes, two dimethylglyoxime radicals lie in the equatorial plane and are joined via the intramolecular hydrogen bond O–H···O. The complexes with pyridine and aniline have similar configurations but different crystal structures.

Mossbauer spectra of nine transition metal carbido carbonyl clusters containing cobalt and rhodium atoms along with iron atoms were measured and analyzed. It is shown that the spectra, depending on cluster composition, are a superposition of different number of quadrupole doublets (up to four), for which the chemical shift varies from 0.12 to 0.34 mm/sec and the quadrupole splitting varies from 0.15 to 1.35 mm/sec. The relationship between the spectrum shape and parameters and the cluster structure, in particular, the coordination number of the iron atoms is established.

A procedure was developed for preparing 4,5;7,8-dibenzo-1,3,2-diazaphosphocanes containing trivalent and pentavalent phosphorus atoms. The structure of the compounds was determined by NMR spectroscopy and single crystal X-ray diffraction. The conformational transitions of the diazaphosphocanes in solution were analyzed. First data were obtained on transformations of the obtained eight-membered heterocycles.

Isostructural crystals of aluminum hexamolybdenocobaltate(III) and hexamolybdenocromate(III) Al[MMo6O18(OH)6] · 16H2O (M = Co(III) and Cr(III)) were studied using X-ray diffraction analysis. These compounds crystallize in the triclinic system: space group P\(\overline 1\), Z = 1, ρ(calcd) = 2.665 and 2.611 g/cm3, respectively. The unit cell parameters were determined: for aluminum hexamolybdenocobaltate(III), a = 6.796(1) A, b= 11.248(2) A, c = 11.568(2) A; α = 101.36(2)°, β = 96.95(2)°, γ = 102.23(2)°; for aluminum hexamolybdenocromate(III), a = 6.838(1) A, b = 11.312(2) A, c = 11.605(2) A; α = 101.29(3)°, β = 97.13(3)°, γ = 102.15(3)°.

The macrocyclisation reaction of 3,3′-(3,6-dioxaoctane-1,8-diyldioxy)-bis(2-hydroxy-benzaldehyde) ( 1 ) with S-methylisothiosemicarbazide hydroiodide in the presence of barium triflate, followed by addition of oxovanadium(IV) chloride, yields the dimeric complexes [VOBaL 1 I(I 3 )CH 3 OH] 2 (3) and [VOBaL 1 (CF 3 SO 3 ) 2 (CH 3 OH) 0.5 (H 2 O) 0.5 ] 2 ( 4 ). Starting from 3,3′-(3,6,9-trioxaundecane-1,11-diyldioxy)-bis(2-hydroxybenzaldehyde) ( 2 ), and following the same procedure the polymeric complex {[VOBaL 2 Cl](I 3 )} n ( 5 ) has been obtained. Treatment of 3 , 4 or 5 in chloroform with an aqueous solution of guanidinium sulphate leads to VOL 1 ( 6 ) or VOL 2 ·2H 2 O ( 7 ). Compound 4 has been synthesised in high yield by direct complexation of VOL 1 with barium triflate in methanol. The crystal structures of 3 , 4 and 5 have been determined by X-ray crystallography. Electronic, mass and EPR spectra are reported.

Self-condensation of 1-phenyl-butane-1,3-dione mono- S -methylisothiosemicarbazone ( 6 ) in the presence of nickel(II) acetate in methanol gives rise to a mixture of two complexes: [2,9-bis(methylthio)-5,13-dimethyl-7,14-diphenyl-1,3,4,8,10,11-hexaazacyclotetradeca-2,4,6,9,11,13-hexaenato(2-) N 1 , N 4 , N 8 , N 11 ]nickel(II) ( 7 ) and [1-amino-1,6-bis(methylthio)-4,9-dimethyl-11-phenyl-2,3,4,7,8-pentaazaundeca-1,3,6,8,10-pentaenato(-)-11-olato(-) N 2 , N 4 , N 8 , O ]nickel(II) ( 8 ). Both the macrocyclic complex 7 and the open-chain chelate 8 are characterised by X-ray diffraction methods, which reveal their square-planar structure. Electronic, IR, NMR, electron impact mass spectra and cyclic voltammograms of new compounds are also reported.

2,3-Dihydrothiazolo[3,2-d]tetrazolium perchlorates have been synthesized by the interaction of 1-phenyl-5-tetrazolesulfenyl chloride with styrene and with (E)-1-phenylpropene in nitromethane in the presence of lithium perchlorate.

Reaction of pentafluorophenyl(diphenyl)phosphine with nitrilimines is a multistep process leading to formation of unstable fused heterocycles with a fluorophosphorane moiety as primary products. Their hydrolysis involves opening of the heteroring and subsequent cleavage of the N-N bond in intermediate phosphorylated hydrazones. The final products are diphenyl(6-arylamino-2,3,4,5-tetrafluorophenyl)phosphine oxides.

1,5- and 2,7-dihydroxynaphthalenes were reacted with P(III) amides to obtain naphthocyclophanes. The structures and chemical properties of the products were studied.

Sodium iodide complexes of 16-membered dibenzoazocrown ether (complex I) and dibenzoazoxycrown ether (complex II) have been synthesized and their structures determined by X-ray method. Stoichiometry of both complexes is 1:1 (ligand: salt); the cation is coordinated to oxygen atoms of the oxyethylene moieties and to one nitrogen atom of azo group in the first, or to oxygen atom of the azoxy group in the last complex. Selectivities of membrane electrodes doped with ion carriers, including 16-membered azocrown and azoxycrown ethers have been compared and discussed mainly in terms of features of crystal structures of carrier complexes.

A comparative assessment was made of the reactivity of carbonyl-containing spirohydrochromans in their reaction with hydrogen sulfide under the conditions of acid catalysis. The special features of the structure of one of the obtained condensed spiro(thia)chromans are examined on the basis of the results from x-ray crystallographic analysis, the13C NMR spectra, and quantum-chemical calculations.

16-Membered dibenzoazo- and dibenzoazoxycrown ethers have been synthesized. The Z and E isomers of the azocrown compound have been separated and the geometry of the –N=N– and –-N(O)=N–- groups determined. Potassium iodide complexes of the azo- and azoxycrown ethers were obtained and their structures were determined by the X-ray method. The crystal of the azocrown ether complex is triclinic, space group P¯1, a = 21.071(5), b = 12.112(4), c = 8.757(2) A α = 81.28(2), β = 84.66(2), γ = 107.49(2)°. The azoxycrown ether complex is monoclinic, space group C2/c, a = 15.648(3), b = 19.597(4), c = 14.651(3) A; β = 111.30(3).

A study has been made of oxidation, sulfurization, and other reactions of 3-C-phosphoryl-1,2-O-isopropylidene-α-D-glucofuranose 3,5,6-bicyclophosphites. Methods for the synthesis of new types of α-D-glucofuranose diphosphorus derivatives were proposed on the basis of these transformations. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9: 631–636, 1998

A reliable method for identification of the dihydroquercetin flavonoid is proposed on the basis of its complex structural study.

The synthesis, structure and chemical features of a new class of tricyclic phosphorus-containing heterocycles are reported. Special attention is paid to the dynamics of molecules and their tendency to enter into elimination reactions. A possibility to synthesize relatively stable dibenzo-1,3,2-diazaphosphepene containing a two-coordinated phosphorus atom is considered.

By reaction of copper(II) chloride and bromide with the 1,5-diphenyl-3,7-dialkyl-9-bispidone series, we have synthesized a number of new complex compounds. In the IR spectra of the complexes, the absorption band for the carbonyl group is shifted toward longer wavelengths compared with the original ligands. This shift can be a criterion indicating formation of complexes of the given composition and structure. We have determined the crystal structure of two new complexes. We show that for complexes with alkylmethyl substituents at the nitrogen atoms, significant distortion of the coordination environment of the metal compared with the methyl analog is typical; this distortion is connected with the interaction between the substituents and the halogen atoms. We hypothesize that this type of interaction affects the structure and spectral properties of the complexes is solution.

The structures of dioxaphosphepane (I) and dioxaphosphecane (II) salts prepared by hydrolysis of the corresponding bicyclophosphates have been compared. In both cases, hydrolysis occurs with breaking of the P−O bond of the fragment at the secondary carbon atom of bicyclophosphate. In phosphocycles I and II, the endocyclic bond angles O−P−O are 104.2 and 104.9°, and the exocyclic ones are 117.7 and 118.6°, respectively. Conformations of the anions in I and II differ substantially: for I it is a “twist” conformationC1TC4, and for II a “distorted armchair.” The data obtained are compared with those found earlier for similar molecules.

Aluminum hexamolybdenocobaltate and hexamolybdenochromate of the Al[MMo6O18(OH)6] · 16H2O composition, where M = Co(III) or Cr(III), were synthesized for the first time. X-ray diffraction study shows that the crystals of the compounds are triclinic; space group P1, Z = 1, and ρcalcd = 2.665 and 2.611 g/cm3, respectively. The compounds were studied by IR spectroscopy and thermogravimetry.