Volume 37, Issue 9

The reaction of the carbonyl metal hydrides (π - C 5 H 5 )M (CO) 3 H(M = Mo, W) with Ph 2 S = XH gives the ainine-isoeyanato compounds (π - C 5 H 5 )(CO) 2 M(NH 3 )NCO. N-Carbaxnoyl-B,S-diphenylsulfilimine Ph 2 S N-C(O) NH 2 has boon isolated from the reaction of the hexacarbonyls M(CO) 6 (M=Cr,Mo) with Ph 2 S = XH. The spectroscopic data (IR, 1 H, 13 C NMR, MS) are reported and the formation of the products is discussed.

The tetraorganodistibanes Pr 4 Sb 2 and Ph 4 Sb 2 were prepared by dehalogenation of the corresponding dioganoantimony bromides with magnesium in tetrahydrofuran. Mass spectra show that the distibanes Me 4 Sb 2 , Et 4 Sb 2 and i-Pr 4 Sb 2 react with air to yield the compounds of the formula R 4 Sb 2 O (R = Me, Et, i-Pr), which are assumed to be bis- (diorganoantimony)oxides. The species (Me 2 Sb) 2 O is also formed by hydrolysis of Me 2 SbBr. Ir and 1 H NMR data of this oxide confirm the proposed structure. The distibanes R 4 Sb 2 (R = Me, Et, Pr, Ph) react quantitatively with sulfur to yield the corresponding bis- (diorganoantimony)sulfides (R 2 Sb) 2 , as derived from ms, NMR and IH data. Ms data of the distibanes R 4 Sb 2 (R = Me, Et, i-Pr, Bu, Ph) are reported and discussed.

The photo-induced reaction of CpFe(CO) 2 Et (1) with either trimethylphosphane or trimethylphosphite (L) in solution results in formation of the substitution products CpFe(CO)(L)Et (3), CpFe(L) 2 Et (5), and the hydrido complexes CpFe(CO)(L)H (4), and CpFe(L) 2 H (0). In contrast, the thermal reaction of 1 with L yields the adduct CpFe(CO)(L)COEt (7) and the dimeric compound Cp 2 Fe 2 (CO) 3 L. Under photochemical conditions, the terminal carbonyl ligand in 7 can be replaced by L to give the derivative CpFe(L) 2 COEt (8). According to a crystal structure determination of CpFe(PMO 3 ) 2 COEt, the complex possesses a η 1 -bonded propionyl ligand. The IR and NMR data, however, are indicative for a η 2 -bonded propionyl ligand.

The preparation of sulfur dioxide complexes M(SO 2 ) 2 (AsFe) (1 a-1 g M = Mn, Fe, Co, Ni, Cu, Zn, Mg) is possible in liquid SO 2 (a) by oxidation of the metals with AsF 5 , (b) by metathesis of metal halides, e.g. NiBro, with AgAsF 6 , (c) by the reaction of metal fluorides, e.g. ZNF 2 , with AsF 5 . The spectroscopic properties of these complexes are discussed and the structure of [Mg(SO 2 ) 2 (AsF 6 ) 2 ] n (1 g) is reported.

PPh 4 [SnCl 3 ] and PPh 4 [SnBr 3 ] were prepared by reaction of PPh 4 X with SnX 2 in CH 2 X 2 solutions (X - Cl, Br). The vibrational spectra of the [SnX 3 ] ⊖ ions show three SnX 3 stretching frequencies, which is caused by deviations from the ideal C 3v symmetry. In the crystal structure determinations these deviations show up by slightly different Sn-X bond lengths which are explained by differing hydrogen bridges to phenyl-H atoms. The isotypic crystal structures of both compounds were determined and refined from X-ray diffraction data (R values: 0.042 and 0.034). Although triclinic (space group P1̄), the structures are closely related to the tetragonal AsPh 4 [RuNCl 4 ] structure type. Very pure SnBr 2 is prepared by the reaction of PPh 4 [SnBr 3 ] with AlBr 3 in CH 2 Br 2 solution.

The laser Raman spectrum of matrix-isolated As 4 -tetrahodra is reported. The frequencies are different to former data obtained by gas-phase measurements.

Crystalline CuAlCl 4 was prepared from CuCl and AlCl 3 in a quartz tube at 533 K. The crystal structure was determined [P4̄2c, a = 543.0(1), c = 1009.6(1) pm, Z = 2, R w =0.034 for 345 reflections]. The chlorine atoms form a distorted cubic close-packed lattice, with copper and aluminium each occupying an eighth of the tetrahedral holes (site symmetries 4̄ and 222, respectively).

By fluorination of CsFeBr 4 · 2 H 2 O we obtained a new modification of CsFeF 4 (a = 12,491(1), c = 13,272(1) A, Z - 20), which according to powder data crystallizes tetragonally in the structure type of β-RbAlF 4 , space group I4̄c2. The same structure type is adapted by CsCoF 4 (a 12,478(1), c = 12,971(1) Å, Z = 20); in contrast RbCoF 4 has similar lattice constants (a = 12,222(1), c = 12,356(2) Å, Z = 20), but another unknown structure; KCoF 4 (a = 7,520(1), b = 7,584(1), c = 5,792(1) Å, Z = 4) crystallizes orthorhombic by isotypic to RbFeF 4 , and NaCoF 4 (a - 4,965(1), b = 5,51(5(1), c = 10,800(2) A, Z = 4) is isotypic to NaTiF 4 . The first compound LiM III F 4 (M III = 3dmetals) is LiCoF 4 , which probably crystallizes monoclinicly (a = 5,540(3), 6 = 4,665(1), c = 5,447(3) Å, = 114,25(5)°, Z = 2). The colour of these cobaltates(III) is violet.

The electrochemical reduction and oxidation of sulfurdiimines R 1 -NSN-R 2 (R 1,2 = C 6 H 5 , C 6 F 5 , C 6 H 5 S, C 6 F 5 S) in organic solvents is studied. Both reactions proceed in the sulfur-nitrogen system in a one-electron step. The influences of the substituents are, however, different.

Tin(II) ethylene glycolate is prepared from freshly precipitated “tin(II)-hydroxide” on heating in ethylene glycol under reflux. The colourless single crystals, slightly distorted cubes, exhibit rhombohedral symmetry (R3̄-C 3i 2 , a h = 1547.7 pm, c n = 871.6 pm, Z = 18). The structure is a 3-dimensional networks of linked tin(II) ethylene glycol chelates.

Substitution of CO in LNi(I)CO (1) (L = h 5 -C 5 H 5 ) by the co-chloro-l-(diphenylphosphino) alkanes Cl-[CH 2 ] n -PR 2 (2a-d) [R = C 6 H 5 ; n = 1(a), 2(b), 3(c), 4(d)] leads to the formation of the intermediates for cyclisation LNi(I)PR 2 -[CH 2 ]nCl (3a-d). When 3a is treated with sodium amalgam, the dimeric phosphino methanide complex [LNiPR 2 CH 2 ] 2 (4′a) is formed. On the basis of an X-ray crystallographic investigation 4'a has a boat conformation and crystallizes monoclinicly in the space group P2 1 /c with Z = 2. The monomeric species (4a) could not be observed. Five- and six-membered I 1 nickelacycloalkanes of the type (4c, d) are obtained by reductive cycloelimination of 3c, d. Because of ring strain the nickelaphosphacyclobutane 4b is not accessible under the necessary cyclisation conditions. Into the Ni-C a bond of 4c, d SO 2 can be inserted to give the cyclic sulfinato complexes (5c, d).

The first complexes containing a manganese-nitrogen triple bond, nitrido(octaethylporphinato) manganese(V) [MnN(OEP)]** and nitrido[meso-tetra(p-tolyl)porphinato]manganese( V) [MnN(TTP)], are prepared by hypochlorite oxidation of the corresponding methoxomanganese( III) porphyrins, Mn(OEP)OMe and Mn(TTP)OMe, in the presence of ammonia. The red, pentacoordinated, diamagnetic species are identified by UV/VIS-, IR-, 1 H NMR, and mass spectra. While the isoelectronic oxochromium(IV) or oxomolybdenum( IV) porphyrins behave as weak oxidants or reductants, respectively, the nitridomanganese( V) unit in the square pyramidal environment is chemically remarkably stable.

The amalgams of lithium, sodium, potassium, barium and zinc were prepared electrochemically (potentiostatic and galvanostatic, see Tables I and II). The potentials of these were measured in acetonitrile, THF and DMF, using the corresponding Perchlorate (Li, Na, K, Ba, Zn) or tetrabutylammonium perchlorate as electrolyte and a standard calomel olektrode (SCE) (Table III). In the case of the lithium amalgam, the dependence of the potential on the lithium content was studied (Table IV). The potential moves slightly to more positive values on dilution, dilution by a factor of 100 producing a shift of only ca. 100 mV.

By means of appropriately D and 13 C labelled precursors it is shown that the proton catalysed degradation of [2,2,6,6]-tetramethyl cyclohexanone {e.g. elimination of acetone and formation of protonatecl acetone from [MH] + ) proceeds via two distinct pathways. The energetically favoured one (pathway A, Scheme 1) involves a sequence of [1,2]-methyl migration, ring contraction and methyl migration, whereas the energetically less attractive path B commences with a Wagner-Meerwein ring contraction, followed by hydroxyl and methyl migration. Semi-empirical quantum mechanical calculations (MNDO) are em-ployed to explore computationally relevant parts of the potential energy surface. The syntheses of the specifically 13 C labelled title compounds (1 a, b) are described in detail.

By analyzing the melting point diagrams of some methylhalogenosilane-pyridine systems the existance of the stable addition compounds CH 3 SiCl 3 · 2 py, CH 3 SiBr 3 · 2 py, (CH 3 ) 2 SiBr 2 · py, (CH 3 ) 3 SiBr · py was proved. In the systems (CH 3 ) 2 SiCl 2 /py and (CH 3 ) 2 SiBr 2 /py unstable 1:2-complexes are also found. (CH 3 ) 3 SiCl forms no complexes with pyridine.

The reaction of phosphonyltriazenes with benzene in the presence of aluminiumchloride is involved with the elimination of nitrogen and followed by electrophilic substitution of benzene. The arylation reaction obviously proceeds via the intermediate formation of arene diazonium ions. Phosphinyltriazenes display the same chemical behaviour.

The kinetics of the reactions of CO 2 + OH → HCO 3 - (i) and barbituric acid →barbiturate anion + H + (ii) have been remeasured using as a new approach the pulse radiolysis technique with optical and conductivity detection. The rate constants obtained in the present study, k i (21 °C) = 6900 ± 700 M -1 s -1 and k ii (19 °C) = 22 ± 2 s -1 agree within experimental errors with values obtained earlier by other methods.

The reaction of 1- (1) and 2-adamantyl malonaldehyde (2) with suitable electrophiles and nucleophiles yields adainantyl-substituted open-chain (3-5), carbocyclic (6) as well as heterocyclic compounds (7-19) with peculiar properties due to the presence of the lipophilic adamantyl group. The tetrazolo[1,5-a]pyrimidine (16) exhibits a solvent-dependent tetrazolo-azido valence isomerization reaction.

Oxidation of 3-alkyl- and 3-arylsubstituted 4-hydroxy-2-quinolones (1) by irradiation with UV light, reaction with 3-chloro-peroxybenzoic acid or hydrogen peroxide in alkaline solution leads to 3-hydroxy-3-substituted quinoline-2,4-diones (2).

Compounds are herbicides with high activity. Methods for synthesis are reported.

The principle of minimum chemical distance (PMCD) is derived from the general theory of the BE- and R-matrices, and makes precise the vague classical “principle of minimum structure change”. In fact, the PMCD may be seen as the principle of minimum structure change in mathematical terms. It provides a quantitative measure of chemical similarity of isomeric molecular systems. Its applications lie in the fields of correlations of substructures, elucidation of reaction mechanisms, and evaluation of synthetic pathways as is illustrated by examples. The mathematical foundations of the computer assisted application of the PMCD are presented.

Solid NaNO 2 and an onium salt react with Fe(CO) 5 and Co 2 [(CO) 8 ] in nonpolar solvents yielding Q[Fe(CO) 3 NO] and Q[Co(CO) 4 ] (Q = onium cation)

Lithium-pentacarbonyl(diethylaminoacyl)- tungstate reacts with SOCl 2 to give trans-tetracarbonyl (chloro) (diethylaminocarbyne) tungsten.

Cyclooctasulfur, S 8 , dissolved in CS 2 reacts at 130-155 °C in sealed ampoules to give S 6 and S7 whose concentrations have been determined by HPLC. The half-time of the reaction is independent of the initial S 8 concentration and decreases from 232 min at 130 °C to 64 min at 150 °C. After long reaction times equilibrium concentrations are observed which are in agreement with the law of mass action. From the temperature dependence of the equilibrium constants the following reaction enthalpies (at 130-155 °C) have been calculated: 3/4S 8 ⇌S 6 ⊿H°=24kJ/mol 7/8S 8 ⇌S 7 ⊿H°=21kJ/mol