Volume 33, Issue 1

1,3-Diorganyl-2,2-dimethyl-I,3,2,4λ 2 -diazasilastannetidines can be prepared as monomers (organyl = tert-butyl) or dimers (organyl = isopropyl) in nonpolar solvents, depending on the organic nitrogen substituent. The formation of the dimer, which is due to an intermolecular Lewis-acid-base interaction of Sn(II) with nitrogen, can be initiated by solidification. When the tertf-butyl compound is cooled below 0 °C two crystalline modifications are found: a monoclinic phase (C 2/c; a= 10.655(5); b = 24.75(1); c = 17.334(9) Å; β = 106.9(1)°) and a triclinic phase (P1̄; a = 10.68(1); b = 13.51(1); c = 12.36(1) Å; α = 96.2(1); β = 102.6(1); γ = 118.4(1)°). The crystal structures turn out to be built of dimeric and monomeric units in the first case and presumably only dimeric species in the second case. The isopropyl derivative crystallizes in the space group P 2 1 /b (a = 10.77(1); b= 12.14(2); c = 11.15(2) Å; β = 120.2(2)°) with only dimeric units being present, as in the liquid. Interrelationships between the three structures are discussed.

The crystal and molecular structure of the monoclinic phase of 1,3-di-tert-butyl-2,2-dimethyl-1,3,2,4λ 2 -diazasilastannetidine has been determined from three-dimensional X-ray data collected on a two-circle diffractometer at -120 °C (MoKa radiation, 2623 reflexions, R - 0,050). The crystals are monoclinic, space group C2/c, with cell dimensions a = 10.655(5), b = 25.75(1), c = 17.33(1) Å, β = 106.8(1)° and Z = 12. Four monomeric (crystal site symmetry 2 (C 2 )) and four dimeric units (crystal site symmetry 1̄ (C i )) are present in the structure interacting over tin-tin (3.68 Å). Remarkable are the very short Sn-N bond (2.09 Å) in the monomer and the donation bond Sn-N (2.39 Å) in the dimer. The coordination of the tin atoms in the different units is discussed in detail.

The reactions of 1,3-di-tert-butyl-2,2-dimethyl-1,3,2,4λ 2 -diazasilastannetidine (1) with O 2 and S 8 or SnCl 4 proceed in two steps: In a first redoxtype reaction an intermediate containing tetravalent tin is formed. Some of these intermediates are unstable with respect to the starting material stannylene 1 and undergo a substitution reaction to yield a spirotetraazastannane. Under appropriate conditions the intermediate from the sulfur- and SnCLi- reaction can be isolated and turns out to be either dispiro[3,3,3]distanna-disulfadisila- tetrazane or a diaza-dichlorostannane respectively. Crystal and kinetic data of some products/reactions are reported.

Polyborates, Ammonium Borates, Isopolyanions, Tris(methoxy)borane, Hydrolysis The preparation of polyborates with bulky cations in organic solvents by the method of "ester hydrolysis" as well as by the method of evaporation of solutions of the base and boric acid reactands under reduced pressure with the very strong bases benzyltrimethyl-ammonium hydroxide and benzyltriethylammonium hydroxide leads to [C 6 H 5 CH 2 N(CH 3 ) 3 ][B 5 O 6 (OH) 4 ] and [C 6 H 5 CH 2 N(C 2 H 5 ) 3 ][B 5 O 6 (OH) 4 ]. The more bulky, but less basic tri-n-butylamine yields a heptaborate, presumably [(C 4 H 9 ) 3 NH][B 7 O 6 (OH) 10 ]. The less bulky, but more basic triethylamine or tri-n-propylamine yield [(C 2 H 5 ) 3 NH][B 5 O 6 (OH) 4 ] or [(C 3 H 7 ) 3 NH][B 5 O 6 (OH) 4 ]. The most bulky, but less basic benzylamine or tri-n-octylamine are not capable to function as cations in polyborates.

The interaction of N,N'-dimethylacetamidine with trialkyl derivatives of aluminium, gallium and indium yields dialkylmetal compounds of the structural formula R 2 M(N 2 Me 2 CMe) (M = Al, Ga and In). According to the vibrational data the M 2 N 4 C 2 skeletons of these dimeric products form a centrosymmetric puckered eight-membered ring, probably with C 2h symmetry. The IR-and Raman spectra of the amidine HN(Me)C(= NMe)Me are discussed.

Alkaline Solvolysis, Trichloroacetate Ion The alkaline solvolysis of trichloroacetic acid in water-ethanol mixtures have been studied in the presence of 0.40-0.80 M sodium hydroxide within the temperature range 35-70 °C. The rate constant increased with progressive addition of the organic solvent. The dielectric constant effect on the reaction rate was investigated. The radius of the activated complex at different temperatures was calculated. The isocomposition and isodielectric energies as well as the thermodynamic parameters of activation were calculated and their significance in terms of solvent composition has been discussed. It was concluded that the reactant state is extensively higher solvated than the transition state by the highly polar (water) solvent.

LiBeSb and LiZnBi have been prepared and analytically and structurally characterized. We found a Wurtzit-type lattice with an ordered arrangement of the positions of Be and Sb respectively Zn and Bi.

The hitherto known antimony oxides Sb 2 O 3 , Sb 2 O 4 and antimony pyrochlore are converted at higher temperatures under high oxygen pressure in the presence of water into Sb 2 O 5 I, Sb 2 O 5 II, Sb 2 O 4,4 (OH) 1,2 and Sb 2 O 4,8 (OH) 0,4 .

The title compounds were prepared by reaction of dimethylaminoalane with mercury - (II) dibromide and diiodide, respectively, and investigated by X-ray diffraction. Both compounds build structures isotype with that of dichloro(dimethylamino)alane. The molecules exist as dimers with a planar four-membered ring of alternating aluminium and nitrogen atoms. These atoms are four-coordinated. The following bond lengths are found: Al-N 1.94 and 1.95 Å, Al-Br 2.26 Å, Al-I 2.49 Å, N-C 1.50 and 1.55 Å.

The synthesis of the sulfinato derivatives 1-7 of pentavalent VB-elements follows equation (2). These compounds differ significantly in their physical and chemical properties and in their structures. In between the extremes of the purely ionic tetramethylam-monium sulfinates la-c and the typically covalent and pentacoordinated tetraorganyl-sulfinato-O-stiboranes 6-7, there are the hexa-or pentavalent compounds of phosphorus and arsenic 2 and 4 or 3 and 5 with sulfinato-O,O' or sulftnato-O linkage, which dissociate readily into their ionic components. 1 a-c are suitable for the synthesis of sulfones according to equation (3). All of the methylsulfinato derivatives can be easily transformed (equation (4)) into the corresponding sulfonates by air oxidation. Only the tetraphenylsulfinato-O-stiboranes 7 a-c show SO 2 -elimination forming pentaorganylstiboranes (equation (5)). IR, mass and in some cases NMR spectra are reported.

The complex formation between Cu 2+ ions and 1,3-diamino-2-propanol has been studied potentiometrically at 25 °C, constant ionic strength equal to 0.1 M NaClO 4 , and pH 5-11. The nature of the complexes has been established by examining the standard deviations and values of the agreement index R of different models.

The ESR spectroscopy is used for the study of the motion of Cu(en) 2 2+ and Cu(tmen)(OH) 2 in fully hydrated X and Y zeolites. At room temperature steric hindrance in the faujasite cavities and slow motion condition lead to partially anisotropic spectra. In frozen samples, calculation of bonding coefficients indicate small interaction with surface walls.

The title compound, PHZ, can be viewed as 1,5-diazacyclooctane (daco) having carbon-3 and carbon-7 fused to benzene rings restricting the vibrational freedom of these carbons and rendering the axial positions in the complexes open for fifth and sixth coordination. Copper(II), nickel(H) and zinc(H) complexes of PHZ have been prepared. Copper(II) formed mono-and bis-complexes, whereas nickel(H) and zinc(II) formed only bis-complexes. The diamagnetic nickel(II) complexes are planar like the corresponding complexes of mesocyclic diamines, daco and dach. The copper(II) complexes differ appreciably from the mesocyclic diamine complexes of copper(II). Zinc (II) formed tetra-hedral complexes with two monodentate PHZ ligands and anions in the first coordination sphere. The structures of the complexes have been assigned by analysis of their spectral, magnetic and conductance data. The thermogravimetric studies of the complexes are also reported and discussed.

The arylazo derivatives (2) of 3-methyl-2-isoxazolin-5-thione were prepared. Alkylation of 2 with alkyl halides results in the formation of the S-alkyl derivatives (5). The S-acetate esters undergo thermal isomerisation to the corresponding 1,2,3-triazole derivatives (6). The thiones 2 condense with hydrazines and primary amines to afford the corresponding 5-hydrazones and 5-imines (8) and (10), respectively. Treatment of 2 with hydrazine hydrate and Phenylhydrazine in boiling alcohol effects ring cleavage with the formation of 9.

Derivatives of 5H-cyclopenta[2,1-b:3,4-b']-dipyridin-5-one including representatives of the new heterocyclic diquaternary system 4H-7a,9a-diazoniacyclopenta[def ]phenanthrene have been synthesised and the herbicidal and redox properties of the salts studied. The mass spectrum of 5-hydroxy-5-methyl-5H-cyclopenta-[2,1-b: 3,4-b'Jdipyridine is also reported.

Ten new quaternary pyridinium salts with urea or carbamate group were prepared and the acidity constants determined. On addition of base to the salts ot pyridyl-urea, stable inner salts could be isolated.

Carbon Subsulphide, 2-Aminopyridine, N-Phenylbenzamidine, ß-Aminocrotonate Carbon subsulphide, C3S2, reacts with 2-aminopyridine (la) and N-phenylbenzamidine (lb) to yield the corresponding higher condensed derivatives 4 and 7. Attempts to obtain mesoionic compounds by reaction of N-substituted 2-aminopyridines or N,N'-disubsti-tuted benzamidines were not successful. Efforts to yield a pyridinethione derivative by reaction of C3S2 with /?-aminocrotonate (lc) failed. In this case the sulphur-bridged compound 8 could be isolated.

⊿G c ≠ values derived from temperature dependent 1 H NMR of phenyl substituted cyclopentadienes show a dramatic increase by immobilizing two phenyl-rings. This phenomenon is explained by an increase in the transition state energy level whereas the ground state is hardly affected.

NMR spectra of several cyclohexenone epoxides obtained by oxygenation of 4-R-2,6-di-tert-butylphenols have been assigned, using substituent induced shifts, offresonance and C - H single-frequency-decoupling techniques, as well as completely C - H coupled spectra. For the -butyl signals the following sequence rules are relevant: methyl carbons and protons = δtBu-C-olefinic(sp 2 ) > δtBu-C-oxirane(sp 3 ) ≥ δtBu-C-OH(sp 3 ); quaternary carbons = δtBu-C-OH(sp 3 ) > δtBu-C-olefinic(sp 2 ) > δtBu-C-oxirane(sp 3 ). In these compounds, the oxirane oxygen causes a highfield shift of the signal of the quaternary C-atom of the feri-butyl group as compared with the influence of a hydroxy group.

The synthesis of α,α'-dihalogenated benzoin ether 6 and benzildimethylmonoketals 7 are discribed. Their reaction behavior under UV irradiation and electron impact conditions are discussed in comparison with those of arylesters 1 of seleno and thiobenzoic acid. The photoproducts of 6 and 7 are separated and identified with help of column or vaporphase chromatography. Photoinduced α-cleavages of 6 and 7 produce 2-halogenbenzoyl radicals 9 and a-monomethoxybenzyl radicals 10 or α,α-dimethoxybenzyl radicals 15 resp., which undergo four different stabilization reactions under formation of 1) 2-halogenbenzaldehydes 12 from 9 by hydrogenabstraction, 2) 2,2'-dihalogenbenzils 11 and 1,2-di(2-chlorophenyl)-1,2-dimethoxyethan (13) via dimerization of 9 or 10 resp., 3) methylesters 16 of 2-halogen-benzoic acids by β-elimination of methylradicals from 15, and 4) 2-halogenacetophenones 17 via combination of 9 with methylradicals from 15. In addition to these photoproducts 2-phenylbenzoic acidester 18, benzaldehyde (19), and acetophenone (20) are formed by photosubstitution of halogens in benzaldehydes 12 as well as in acetophenones 17 against hydrogen and in benzoic acid-esters 16 against phenyl resp. Independent photoexperi-ments prove 1) the formation of 2-phenylbenzoic acidester 18 by halogen-phenylreplace-ment in 16 and 2) that chlorine is easier than bromine, both in ortho-position to a carboxyl function, substituted by phenyl. No photoproducts {e.g. 8 or 14) are formed by substitution of halogen in the 2-halogenbenzoyl part of a-cleavage against neither a-monomethoxybenzyl nor a,a-dimethoxybenzylradicals resp. as expected like the photoinduced formation of selenoxanthones or thioxanthones 2 from selenol-or thiolesters 1.

The compounds KMnSb, KMnBi, NaMnP, NaMnAs, NaMnSb and NaMnBi crystallize in a Cu 2 Sb-type-structure, spacegroup P4/nmm-D 7 4h . The preparation is described and cell constants are given.

By phase analysis in the ternary systems Li-Zn(Cd or In)-Sn(Pb) several nonvalent cubic phases were found. Structure deter-mination on Li 7.72 Zn 4.28 Sn 4 showed that the phases crystallize in a modified NaTl-type-lattice.

2,2'-Selenodipyridine on reaction with dibromomethane affords the new polycyclic system, 6H-dipyrido[2,1-b :1',2'-e]-1,3,5-selenadiazinium dibromide.

The monomelic and readily soluble compounds R 2 PO 2 Re(CO) 3 diphos (1a, b) [R = CH 3 : (a); C 6 H 5 : (b)], in which diphos and R 2 PO 2 - are linking bidentate i.e. unidentate to rhenium, are obtained by reaction of [R 2 PO 2 Re(CO) 3 THF] n with diphos. Heating 1 a to 110 °C the polymeric complex [(CH 3 ) 2 PO 2 Re(CO) 2 diphos] n (2) is formed. The IR, Raman, and 31 P NMR spectra are discussed.

Trifluoroperoxyacetic acid reacts in 80% yield with (S 7 N) 2 S to give colorless crystals of the known (S 7 N) 2 SO, and with S 7 NH to give the formerly unknown unstable hepta-sulfurimide 3-oxide, S 7 NHO, the properties and vibrational spectra of which are reported.

Manganese(II) Complex, DOPA The complex formed between manganese-(II) and 3,4-dihydroxiphenylalanine (DOPA) has been prepared. IR spectroscopic in-vestigations and analytical data indicate coordination of the manganese(II) ion through the amino acid end (O,N) of the DOPA molecule.

N-Methylhydroxylamine, Hydroxamic Acids, Nitrosomethane, Formaldoxime N-Methylsulfonyl and N-phenylsulfonyl N-methylhydroxylamine, CH 3 SO 2 N(CH 3 )OH and C 6 H 5 SO 2 N(CH 3 )OH, result from the reactions of methylsulfonyl chloride and phenylsulfonyl chloride with N-methyl-hydroxylamine. The acid and alkaline hydrolysis, IR and 1 H NMR spectra are reported.

Acid-controlled sodium borohydride reduc-tion of imides followed by cyclisation of the carbinol lactams formed affords the title compounds in good yields.

Kinetic energy release measurements dem-onstrate that the loss of neutral HN, EtOC(O)N from the compounds investigated seems to occur by a symmetry allowed (1,1) elimination. lionized nitrenes are produced with only very low intensity.