Volume 49, Issue 5

Single crystals of Sr 3.67 Na 0 . 33 PtO 6 were prepared by heating oxide mixtures in closed silver tubes and investigated by X-ray single crystal techniques. It crystallizes with trigonal symme­try, space group D 6 3d -R3̅c (Nr. 167) with a = 9.6617, c = 11.6580 Å, Z = 6. Sr 3.67 Na 0 . 33 PtO 6 belongs to the Sr 4 PtO 6 type and is isotypic to K 4 CdCl 6 . One point position characterized by a trigonal prismatic O 2- coordination is occupied by Na + and Sr 2+ statistically. The crystal structure is discussed with respect to the related compounds Sr 3 CuPtO 6 and Ca 3. 5 Cu 0.5 PtO 6 .

Single crystals of the phase NaBa 4 Cu 0,5 Pt 1,5 O 8 were prepared in closed silver tubes. The black and moisture sensitive crystals were investigated by four-circle diffractometer X-ray tech­niques. They show trigonal symmetry, space group D 2 3 -P321, a = 10.0644, c = 8.3811 Å, Z = 3 and belong to the perovskites. The typical M 2 C 9 ; double octahedra are occupied by Pt 4+ and Cu 2+ in a different manner. Na + is partly in and out of the centres of trigonal prisms of oxygen. These features will be discussed with respect to the underoccupied point position O(3).

Single crystals of Cu(Mg 2 . 56 Cu 0.44 )Cu(AsO 4 ) 3 have been prepared by CO 2 -LASER technique and investigated by X-ray diffraction methods. The light blue crystals show monoclinic sym­metry, space group C 6 2h -C2/c, a = 11.897, b = 12.855, c = 6.688 Å, β = 113.06°, Z = 4. The structure type is characterized by AsO 4 tetrahedra, dumb-bell-like coordinated Cu(I), twisted CuO 4 square polygons and octahedra statistically occupied by Mg/Cu 2+ .

The μ2-halogeno complexes PPh 4 [X(N-bromosuccinimide) 2 ] and PPh 4 [X(N-bromophthali- mide) 2 ] with X = Cl and Br have been prepared by reactions of N-bromosuccinimide and N-bromophthalimide, respectively, with the corresponding tetraphenylphosphonium halides PPh 4 X in acetonitrile solutions. The compounds form pale yellow crystal needles, which were characterized by IR spectroscopy and by crystal structure determinations. PPh 4 [Cl(N-Bromosuccinimide) 2 ] (1): Space group P2 1 /n, Z = 4, structure solution with 2516 observed unique reflections, R = 0.040. Lattice dimensions at -25 °C: a = 1775.9(1), b = 764.3(1), c = 2341.7(2) pm, β = 101.84(1)°. PPh 4 [Br(N-Bromosuccinimide) 2 ] (2): Space group P2 1 /n, Z = 4, structure solution with 5620 observed unique reflections, R = 0.061. Lattice dimensions at 20 °C: a = 1776.9(9), b = 762.2(3), c = 2331(1) pm, β = 103.02(3)°. PPh 4 [Cl(N-Bromophthalimide) 2 ] (3): Space group P1̅, Z = 4, structure solution with 3812 observed unique reflections, R = 0.039. Lattice dimensions at -50 °C: a = 918.5(2), b = 1115.0(3), c = 2584.4(5) pm, α = 88.22(3)°, β = 83.20(3)°, γ = 85.10(3)°. PPh 4 [Br(N-Bromophthalimide) 2 ] (4): Space group P1̅, Z = 2, structure solution with 3413 observed unique reflections, R = 0.044. Lattice dimensions at -50 °C: a = 1120.2(2), b = 1308.6(3), c = 1343.2(3) pm, α = 105.10(3)°, β = 104.16(3)°, γ = 92.99(3)°. The structures of 1-4 consist of PPh 4 + ions, anions [X(N-bromosuccinimide) 2 ] - and [X(N-bromophthalimide) 2 ] - , respectively, in which the halide ions X - are coordinated by the bromine atoms of N-bromosuccinimide and N-bromophthalimide molecules, respectively. The bond angles Br···X···Br are 86.48(5)° for 1, 85.1(1)° for 2, 102.31(6)° and 93.61(6)° for 3, and 91.86(4)° for 4. The bond angles N-Br···X are nearly linear.

The μ 2 -halogeno complexes PPh 4 [X(N-Iodosuccinimide) 2 ] · CH 3 CN with X = CL Br, I have been prepared by reactions of N-Iodosuccinimide with the corresponding tetraphenylphos- phonium halides PPh 4 X in acetonitrile solutions. The compounds form pale yellow crystal needles, which were characterized by IR spectroscopy and by crystal structure determinations. PPh 4 [Cl(N-Iodosuccinimide) 2 ] · CH 3 CN (1): Space group Pna2 1 , Z = 4, 4461 observed unique reflections. R = 0.027. Lattice dimensions at -60 °C: a = 1840.5(9), b = 2589(1), c = 728.2(4) pm. PPh 4 [Br(N-Iodosuccinimide) 2 ] · CH 3 CN (2): Space group Pna2 1 Z = 4, 4284 observed unique reflections, R = 0.034. Lattice dimensions at -70 °C: a = 724.8(4), b = 1838.6(9), c = 2601(1) pm. PPh 4 [I(N-Iodosuccinimide) 2 ] · CH 3 CN (3): Space group Pna2 1 , Z = 4, 5775 observed unique reflections. R = 0.031. Lattice dimensions at -60 °C: a = 1849.2(9). b = 2644(1), c = 730.3(4) pm. 1-3 are isotypical. There structures consist of PPh 4 + ions, including acetonitrile molecules without bonding interactions, and anions [X(iodosuccinimide) 2 ] - , in which the halide ions X - are coordinated bv the iodine atoms of the N-iodosuccinimide molecules. The bond angles I··· X···I range from 90.13(4)° (X = Cl) and 88.84(3)° (X = Br) to 87.83(3)° (X = I). The bond angles N- I ··· X are nearly linear.

The title compounds have been prepared by reaction of phenyl-, allyl- or amino-substituted disilylmethanes and disilylphenylmethanes with trifluoromethanesulfonic acid. New organo- silicon oligomers and polymers are obtained in good yields and high purities from these silyltriflates and lithium acetylides, triphenylgermyllithium or diphenylsilanediol/triethylamine. In these compounds the carbosilane units are connected by alkyne or siloxane bridges. The structures have been confirmed by NMR spectroscopy ( 29 Si, 13 C, 1 H) and elemental analysis.

The lead(II) complexes of 2,2'-iminodiethanol (H 2 Dea)Pb 2 (Dea)(NO 3 ) 2 (DMF), Pb 2 (HDea) 2 Cl 2 and [Pb 2 Br 6 ](H 3 Dea) 2 (DMF=N,N-dimethylformamide) have been synthesized from the com­ponents and characterized by X-ray crystallography. Both mono- (HDea) and doubly (Dea) deprotonated HN(CH 2 CH 2 OH) 2 are coordinated via oxygen and nitrogen atoms in Pb 2 (Dea)(NO 3 ) 2 (DMF) and Pb 2 (TIDea) 2 Cl 2 . The nitrate complex contains three- and two- coordinate lead(II) atoms linked by μ 2 -bridging oxygen atoms, whilst in the chloride complex four- and two-coordinate metal atoms are also associated by μ 2 -bridging oxygen atoms. In [Pb 2 Br 6 ](FI 3 Dea) 2 the nearest coordination environment of metal atoms consists of bromine atoms only, while the H 3 Dea + cations are not coordinated to lead atoms at all. The structural differences between the coordination environments of the lead atoms are discussed in connec­tion with the inert pair effect. All compounds possess ionic type crystal structures.

Organometallic tin halides R 2 SnCl 2 (R = {Cp(CO) 2 Fe}, {Cp(CO) 3 Mo}) react with Te(SiMe 3 ) 2 to form the compounds [{Cp(CO) 2 Fe} 4 Sn 2 Te 2 ] 1, [{Cp(CO) 3 Mo} 4 Sn 2 Te 2 ] 2 and [{Cp(CO) 3 Mo) 4 Sn 4 Te 6 ] 3. According to crystal structure determinations, 1 and 2 contain planar Sn 2 Te 2 rings. 3 consists of an adamantane-like Sn 4 Te 6 framework.

Three different bis(ethylenediamine) Copper(II) tetraborates have been prepared: Cu(en) 2 [B 4 O 5 (OH) 4 ] · 2B(OH) 3 (A), 2{Cu(en) 2 B(OH) 3 · H 2 O[B 4 O 5 (OH) 4 ]} · H 2 O (B) and {Cu(H 2 O) 2 [B 4 O 5 (OH) 4 ] 2 }(μ-H 2 O){Ag(en) 2 } · (μ-H 2 O){Na(H 2 O) 2 ) (C). The crystal structure analyses of A (monoclinic, P2 1 /c, a = 1282.5(1), b = 1020.8(1), c = 1510.5(2) pm; β = 96.66(1)°, Z = 4), B (monoclinic, Pc, a = 1254.4(1), b = 914.1(1), c = 1594.2(2) pm; β = 94.79(1)°, Z = 2) and C (triclinic, P1, a = 846.3(3), b = 917.9(3), c = 928.1(7) pm; α = 93.71(6)°, β = 104.79(3)°, γ = 103.23(2)°; Z = 1) show that all compounds contain the tetraborate ion [B 4 O 5 (OH) 4 ] 2- . In A and B, there are tetraborate ions and boric acid molecules. The coordination sphere of the Cu 2+ ion is Jahn-Teller distorted, coordinated by 2 en groups with 4 Cu-N distances between 196 and 206 pm, as well as by 2 OH groups with Cu-O distances of 251 to 274 pm. In C, the Cu 2+ ion is surrounded by 6 OH groups, and the Ag + ion by 2 en and 2μ-H 2 O molecules.

The crystal structure of Sr 0.2 Ca 2.8 Tl 2 O 6 has been determined by single crystal X-ray diffraction. The compound crystallizes in space group Pbam (No. 55) with a = 11.228(1), b = 16.471(1) and c = 3.3326(3) Å. It is isostructural with Ca 3 In 2 O 6 and SrCa 2 In 2 O 6 .

Tetrakis[bis(trimethylsilyl)methyl]dialane(4) (1) with an Al-Al bond reacts with LiBr in n-pentane in the presence of chelating N.N.N'.N'-tetramethylethylenediamine (TMEDA) to yield the monobromo adduct [Li(TMEDA) 2 ] + [R 2 Al-AlR 2 Br] - 4. Compound 4 is unstable in ethereal solution and decomposes with quantitative formation of LiBr and the starting compound 1. Crystal structure determination of 4 C 5 H 10 shows a terminal Al-Br bond in an anion with a four-coordinated aluminium atom neighbouring a three-coordinated, coordinatively unsaturated aluminium atom. While the Al-Al bond length is not significantly different (264.3 pm) as compared to the data for 1, the Al-Br bond is rather long (247.6 pm) indicating a weak coordinative bonding.

[O(AuPPh 3 ) 3 ] + BF 4 - has been found to be a powerful aurating reagent for phthalimide, to give (phthalimido)(triphenylphosphine)gold(I) (1) in high yield. Two different crystal sys­tems, with or without CHC1 3 molecules in the unit cell, have been obtained. In both cases the monoaurated diacylamido complex C 6 H 4 (CO) 2 N(AuPPh 3 ) (1) is present as a monomer with linear two-coordinate gold atoms. The N-Au(I) bond lengths (2.028(4), 2.040(4) Å) are similar to those found in other monoaurated complexes of the type R ] R 2 N(AuPPh 3 ) with strongly electron-withdrawing organic substituents R 1 , R 2 . Crystal data: 1, monoclinic, P2 1 /c, a = 9.948(1), b = 15.712(1), c = 14.651(1) Å, β = 103.40(1)°, V = 2227.7 Å 3 , Z = 4; 1·CHCl 3 , orthorhombic, P2 1 2 1 2 1 , a = 8.889(1), b = 10.349(1), c = 29.198(2) Å, V = 2686.0 Å 3 , Z = 4.

The reaction of HAuCl 4 or AuCl 3 with Sn(CH 3 ) 4 in methanol at low temperatures gives [(CH 3 ) 2 AuCl] 2 in yields from 40 to 45%.

Li[PF 6 ] (rhombohedral, R3̅; a = 493.2(2), c = 1265.8(4) pm; Z = 3) and Li[AsF 6 ] (rhom­bohedral, R3̅; a = 501.6(1), c = 1302.8(4) pm; Z = 3) are isotypes of the Li[BiF 6 ] structure. The E v -elements P(As) as well as lithium are in a nearly perfect octahedral coordination by fluorine. The crystal structures of the fluoro-compounds A[E V F 6 ] (A = Li, Na, K, Rb, Cs; E v = P, As, Sb, Bi) can be divided in two groups: i. with A and E v in a NaCl like arrangement and ii. with A and E v in a CsCl like arrangement. The coordination numbers (CN) of the A-sites (CN between 6 and 12) depend on the ratio of radii r(E V5+ )/r(A + ).

Methanolothermal reaction of Cs 2 CO 3 with Ge and Se at 190 °C yields Cs 4 Ge 4 Se 10 · 2 CH 3 OH and Cs 4 Ge 2 Se 8 , the structures of which have been determined by X-ray structural analysis. The anion [Ge 4 Se 10 ] 4 in Cs 4 Ge 4 Se 10 )·2 CH 3 OH displays an adamantane-like structure in which four GeSe 4 tetrahedra are linked via joint vertices. In con­trast Cs 4 Ge 2 Se 8 contains the novel dinuclear anion [Ge 2 Se 8 ] 4- , the first example of a selenidogermanate(IV) exhibiting Se 2 bridging units. Two GeSe 4 tetrahedra are linked in this anion through Se-Se bonds to yield a six-membered ring, which displays a chair conformation and crystallographic C 2h symmetry.

Attempts to coordinate N 2 H 4 to [Fe(S 2 C 6 H 4 ) 2 ] fragments lead to N 2 H 5 [Fe(N 2 H 4 )(S 2 C 6 H 4 )2], which crystallizes from MeOH/N 2 H 4 solutions as the solvate [(N 2 H 5 ){Fe(N 2 H 4 )(S 2 C 6 H 4 ) 2 } · 1,33 N 2 H 4 ]. 1, and has been characterized by X-ray structure analysis. 1 contains three discrete N 2 H 5 + cations, four N 2 H 4 solvate molecules and three independent [Fe(N 2 H 4 )(S 2 C 6 H 4 ) 2 ] - anions which are connected via an extended network of N-H ··· N and N-H ··· S bridges. N 2 H 5 [Fe(N 2 H 4 )(S 2 C h H 4 ) 2 ] and 1 contain high-spin Fe(III) centers and labile N 2 H 4 ligands.

Template 1:1 condensation of 3,5-diacetyl-1,2,4-triazole with thiocarbohydrazide or car- bohydrazide in the presence of 1 equivalent of Pb(SCN) 2 produces mononuclear [2 + 1] com­plexes 1 and 3. The analogous reaction with thiosemicarbazide and semicarbazide produces the dinuclear [1+2] complex 2 and the mononuclear metal free 4. The carbohydrazide deriva­tive 3 reacts with the carbohydrazide or the 1,3-diaminopropane to yield the macrocyclic dinuclear complexes 5 and 6. Direct reaction of 3,5-diacetyl-1,2,4-triazole with thiocarbohydrazide. carbohydrazide, thiosemicarbazide and semicarbazide leads to open [1+1] ligands L 1 , L 2 , L 3 , L 4 , and closed [1+1] ligands (mesocyclic ligands) L 5 and L 6 were prepared by addition of 1 equivalent of LiOH to the reaction mixture. The reaction of open and mesocyclic [1+1] ligands with copper(II) salts gives [CuLX 2 ] and [Cu 2+ L 2- ] complexes. All these compounds have been characterized by 1 H NMR, IR, electronic and mass spectra and by analytical data.

The title compound 3 is formed on reaction of octamethyldispiro[2.1.2.1]octane-4,8-dione (1) with hydrazine. Its structure is established by X -ray diffraction analysis.

Several new 4.7-donor substituted 1.10-phenanthrolines were synthesized and the corre­sponding tris(1,10-phenanthroline)iron(II) complexes were studied by cyclic voltammetry. All iron(II) complexes showed fully reversible waves at scan rates between 50 and 500 mV/s. For some redox systems the kinetics in their reaction with chlorine was studied. Complexes 7k and 71 significantly extent the potential range of tris(1,10-phenanthroline)iron(II) complexes.

The novel cyclopentadiene HMe 4 C 5 CH 2 CMe 2 py [py = 2-(4-tert-butyl)pyridyl] 2H has been prepared from tetramethylfulvene and lithiated 2-isopropyl-4-tert-butylpyridine. Lithiation of 2H with Bu n Li and subsequent reaction with FeCl 2 yields the ferrocene (2) 2 Fe, which crys­tallizes in the triclinic space group P1̅ with a = 8.368(1), b = 8.468(1), c = 14.313(1) Å, α = 80.64(1), β = 86.67(1), γ = 80.12(1)° and V = 985.4(2) Å 3 .

The synthesis of hitherto unknown 3-acetyl-2-hydroxy-1-N,N-diacetylaminocarbazole (3a-f), is reported. The hydroxyiminocarbazoles (2a-f), prepared from 1-oxo-1,2,3,4-tetra-hydrocarbazoles (1a -f) on treatment with acetyl chloride in acetic anhydride yielded the title compounds (3a-f).

Several homonuclear cobalt hydride clusters are accessible by reacting the complexes (η 5 -Cp R )Co(η 2 -ethene) 2 (R = H 5, Me 5 ) 3, 4 with (C 2 H 5 ) 2 AlH followed by alcoholysis of the crude reaction mixtures. Depending on the degree of alkyl substitution, different nuclearities of the resulting clusters have been observed. In the case of the pentamethyl substituted derivative (η 5 -Cp*)Co(η 2 -ethene) 4 a mixture of di-, tri- and tetranuclear cobalt hydride clusters namely [(η 5 -Cp*)Co] 2 H 3 1, [(η 5 -Cp*)Co] 3 H 4 2 and [(η 5 -Cp*)Co] 4 H 4 7 were form­ed and separated by repeated crystallization. When reacting the parent compound (η 5 -Cp)Co(η 2 -ethene) 3 with (C 2 H 5 ) 2 AlH and quenching the reaction mixture with alcohol at low temperature, the tetranuclear cobalt cluster [(η 5 -Cp)Co] 4 H 4 5 is the main product. Aside from this, trace amounts of the cobalt alkylidine cluster [(η 5 -Cp)Co] 4 μ-[C(CH 3 )]H 6 were formed as detected by mass spectrometry. For the first time a direct synthesis of [(η 5 -Cp**)Co] 3 H 4 10 and [(η 5 -Cp**)Co] 4 H 4 11 was achieved by reaction of cobalt atoms with tetramethyl-ethyl-1,3-cyclopentadiene (mixture of isomers) in methylcyclohexane at -120 °C. However, the main product of this metal atom reaction is the mononuclear cobalt sandwich compound (η 5 -Cp**)Co(η 4 -tetramethyl-ethyl-1,3-cyclopentadiene) 9 as a mixture of isomers. The trinuclear cobalt alkylidine cluster [(η 5 -Cp*)Co] 3 μ 3 -[C(CH 3 )] 2 8 is formed when reacting (η 5 -Cp R )Co(η 2 -ethene) 2 3 with equimolar amounts of di-isobutyl-aluminium- hydride or the borabicyclus 9-BBN.

Working in (CD 3 ) 2 SO/MeOH 98:2, 2-methoxy-5-[(4-methylphenyl)azo]-2,4,6-cyclohepta- trien-1-one (1a) was found to add either MeO - , giving the stablegcw-dimethoxy α-adduct 2a, or EtS - , to give initially to the C-2 α-adduct 4 a; on neutralization, the latter gave ipso (C-2) replacement of OMe by SEt, while the former returned to the starting material, via the neutral α-adduct 3a. In contrast, in the same medium, 2-ethylthio-5-[(4-methylphenyl)azo]-2,4,6-cy- cloheptatrien-1-one (5 a) was found to add EtS - at both C-2 and C-7; on neutralization prod­ucts of both ipso substitution (5 a) and ipso- plus tele-substitution (C-7) (8) were isolated.

New muramyl dipeptide derivatives with exchanged carbohydrate residues are described. Each derivative is synthesized via a solid phase synthesis using an aminomethyl anchor resin. All synthetic products can be isolated in good yields. Their biological activities are tested by the luminol-dependent chemiluminescence associated with the phagocytosis of opsonized zymosan by granulocytes.

Pentacarbonyl(η 2 -tetracyanoethylene) metal(0) complexes of chromium, molybdenum and tung­sten have been synthesized by the photochemical reaction of hexacarbonyl metal(o) with tetra- cyanoethylene in toluene at room temperature. The complexes were purified by chromatography and recrystallization, and characterized by UV- visible, IR and 13 C NMR spectroscopy. Tetra- cyanoethylene is symmetrically bonded to the M(CO) 5 unit through its carbon-carbon double bond as an η 2 -ligand. The spectral data are dis­cussed in terms of the metal → ligand π inter­action.