Volume 43, Issue 6

The stepwise interconversions between benzonitrile and benzylamine have been realized in both directions via Ru 3 cluster intermediates. The hydrogenation/dehydrogenation system can be entered from Ph-CN, Ru 3 (CO) 12 , and H 2 yielding HRu 3 (CO) 10 (NCHPh) or from PhCH 2 NH 2 and Ru 3 (CO) 12 yielding HRu 3 (CO) 10 (NHCH 2 Ph), These two clusters can be interconverted by thermal hydrogenation and dehydrogenation, with H 2 Ru 3 (CO) 9 (NCH 2 Ph) as a CO and H 2 depen­dent intermediate. The system can be left only towards benzylamine which is formed in small yields from HRu 3 (CO) 10 (NHCH 2 Ph) at high temperatures and under high CO or H 2 pressures.

The boron hydride B 4 H 10 is prepared in high yields (90%) through hydride-ion abstraction reactions when a mixture of BH 4 - /B 4 H 8 - is treated with CH 3 I or I 2 respectively. A high yield (96%) method for the conversion of B 3 H 8 to B 4 H 10 is the reaction of B 3 H 8 - with AICl 3 solvents which do not have any Lewis base character. The solvents are assumed to react as electron acceptors with the intermediate [B 2 H 5 - ] to form B 4 H 10 , R - and H 2 (R-H = solvent). A 1:1 mixture of B 4 H 10 , and B 5 H 9 is obtained when B 3 H 8 - is treated with CH 3 I or I 2 . The reaction can be viewed to involve an initial step in which unstable “B 3 H 7 ” is generated which immediately undergoes decomposition to give B 4 H 10 , B 5 H 9 and H 2 . Treatment of B 4 H 10 with (n-Bu) 4 NBr results in the formation of B 4 H 7 Br - which decomposes slowly at 0 °C to form B 5 H 9 . An alternative synthesis of B 5 H 9 , via hydride-ion abstraction is possible through the reaction of (n-Bu) 2 O-BF 4 with B 3 H 8 - in ether solvents.

The reaction of (I) 3 (CO)L 2 W≡CNEt 2 (L 2 = 2.2'-bipyridyl(2.2'-bipy); 1.10-phenanthroline (ophen)) (1, 2) with two equivalents of tert-butylisonitrile results in the elimination of the carbonyl group and the displacement of one iodine ligand from the coordination sphere, leading to the new, cationic carbyne complexes [(I) 2 (t-C 4 H 9 NC) 2 L 2 W≡CNEt 2 ] + I - (3, 4). The ionic character and composition of 3 and 4 was confirmed by the electrical conductivity of their solutions as well as by elemental analyses, IR, 1 H NMR and 13 C NMR spectroscopy.

Dehalogenation of bis(diisopropylamino-chloroboryl)methane 1 b with sodium/potassium alloy in petroleum ether yields the 1,2,4,5-tetraborinane 2b (38%), whereas in tetrahydrofuran the five-membered 1-aza-2,4-diborolidine derivative 3a (36%) is formed. The constitution of 2b and 3a follows from spectroscopic data and has been confirmed by X-ray structure analyses.

The cationic diselenium bridged title compound 2 and [{(μ 5 -C5H5)(CO) 2 Fe} 3 Se] + BF 4 - have been isolated from the reaction of (OC) 5 ReFBF 3 with (μ 2 -Se n )[(μ 5 -C 5 H 5 )(CO) 2 Fe] 2 (n = 1, 2). The heterometallic μ-thiolato title complex has been prepared from (OC) 5 ReFBF 3 and (μ 5 -C 5 H 5 )(OC) 2 FeSR (R = Me. Ph; 4). The structures of 2 and 4a have been determined by X-ray diffraction analyses.

An alkali-polyketene-enolate was made from polyketene by using aqueous bases MOH (M = Li, Na, K, Rb, Cs). The structure is proposed on the basis of IR and 13 C NMR spectra, the paramagnetic properties were investigated by EPR spectroscopy. AC conductivity measurements show a maximum conductivity of 10 -2 S cm - 1 (at 115 °C), where marked ionic participation is expected. Doping of the polyacetylene backbone with iodine gives no increase of conductivity; CV measurements indicate the presence of triiodide anions.

WCl 4 (NCl) has been prepared as a red-brown crystal powder by the reaction of tungsten hexacarbonyl with excess nitrogen trichloride in boiling CCl 4 . The complex is associated via chloro bridges, forming dimeric units, according to the IR spectrum. Thermal decomposition at 200 °C leads to tungsten nitride trichloride, WNCl 3 ,. With acetonitrile, WCl 4 (NCl) reacts with formation of the monomeric complex [CH,CN-WCl 4 (NCl)], which was characterized by its IR spectrum as well as by an X-ray structure determination. Crystal data: space group P2 1 /m, Z = 2 (1387 independent observed reflexions, R = 0.07). Lattice dimensions at 20 °C: a = 590.4(3), b = 729.0(3), c = 1124.6(4) pm, β = 100.63(2)°. The complex forms monomeric molecules, in which the tungsten atom has a distorted octahedral environment of four chlorine atoms in equatorial positions, and the acetonitrile molecule in trans-position to the group. Bond lengths WN = 172 and NCI = 161 pm; bond angle WNCl = 175.5°.

Trimetallic complexes Fe(C 5 H 4 -SML n ) 2 (ML n = M(NO) 2 Cp (M = Cr. Mo, W) and M(CO) 3 Cp (M = Mo, W)) containing a ferrocene-1.1'-dithiolato bridge between two group VI metals were prepared and spectroscopically characterized. The mixed species Fe(C 5 H 4 -SCr(NO) 2 Cp)(C 5 H 4 -SW(CO) 3 Cp) and the bimetallic precursors Fe(C 5 H 4 -SML n )(C 5 H 4 -SH), (ML n =M(NO) 2 Cp(M=Cr,Mo), M(CO),Cp(M=Mo,W)). were also obtained. The ferrocene-thiolato ligands are stronger electron-donors than phenyl-and methyl-thiolato ligands.

Bis(9-borabicyclo[3.3.1]nonane) reacts with sulfur to give the bis(1,5-cyclooctanediylboryl)- monosulfide (1) in high yield. The (9-BBN) 2 disulfide 2 is easily prepared from 1 with sulfur. 2, which can also be obtained from 9-Iodo-9-BBN with sulfur, reacts with (9-BBN) 2 to form 1.1 is an excellent sulfidation reagent for preparing thio compounds by S/O-exchange.

The crystal structure of the compound Na-CuCrF 7 (orthorhombic, a = 710.0, b = 1033.8, c = 751.8 pm, Z = 4) was refined in space group Pmnb to R g = 0.028 (1545 independent reflections). The Jahn-Teller distortion of the CuF 6 -octahedra (Cu-F = 191.1/193.8/212.4 pm. mean 199.1 pm) reduces the symmetry compared to the body-centered orthorhombic weberite type, to which it is otherwise closely related. The CrF 6 -octahedra. interconnecting parallel chains of CuF 6 -octahedra, are nearly undistorted (mean Cr-F = 190.6 pm). Na 2 CuFeF 7 exhibits a supercell with a different structure (monoclinic, a = 2468.7, b = 734.7, c = 1245.2 pm, β = 99.29°, Z = 16). It may be interpreted as a new intermediate type between orthorhombic and trigonal weberites. Preliminary results obtained from refinement in space group A2/n (R g = 0.076) are given and discussed (mean values Cu-F = 199 pm, Fe - F = 192 pm).

The 1:1 complexes of Ag[GaCl 4 ] with anti-[2.2](1 ,4)naphthalinophane and of Ag[ClO 4 ] with [2](1.4)naphthalino[2]paracyclophane and rac-[2](1,5)naphthalino[2]paracyclophane have been prepared and characterized by elemental analyses and IR spectra. The crystal structure of the last compound, ([2](1,5)naphthalino[2]paracyclophane)silver(I) Perchlorate, has been determined by X-ray methods. It crystallizes in the centrosymmetrical space group P2 1 /n with cell dimensions a = 12.495(2), b = 8.546(1), c =16.196(2) Å, β = 101.27(1)°. Both enantiomers of the ligands are present in the unit cell and related by centrosymmetry. Each silver atom is connected with the naphthalin systems of two ligands and with two Perchlorate anions, one of which is chelating, while the other is only monodentate. The cation/anion chains are linked through the organic ligands in such a way that a sheet structure is formed. The benzene rings of the cyclophanes are not involved in the metal coordination, the naphthaline rings are μ 3 -bonded to the silver atoms, which are not ring-centered.

Tin-nitrogen heterocycles [1,3,2,4λ 2 -diazasila- (1), -λ 4 -stannetidines (2), spiro-compounds (3, 4), 1,3,2λ 4 ,4λ 4 -diazadistannetidines (5), 1,3,4,5,2λ 2 -diazadisila- (6) and -λ 4 -stannolidines (7)] have been characterized by 13 C, 15 N, 29 Si and 119 Sn NMR spectroscopy [chemical shifts δX and coupling constants n J( 119 Sn-X) (n = 1, 2, 3; X = 13 C, 15 N, 29 Si, 119 Sn]. The influence of the ring size becomes apparent in particular by comparison of the various coupling constants. In the compounds 1 and 6 the presence of a two-coordinate tin atom is reflected by the extremely low shielding of the 119 Sn nuclei and also by the reduced shielding of the 29 Si nucleus. The comparison with δ( 29 Si) data for corresponding non-cyclic compounds indicates that the latter effect may be traced to intra-annular interactions in 1 and 6 which involve the lone electron pair at the tin atom.

The diphosphenyl complex (μ 5 -C 5 Me 5 )(CO) 2 Fe-P=P-Ar (1a) (Ar = 2,4,6-tert-Bu 3 C 6 H 2 ) reacts with an equimolar amount of sulfur to yield the first thioxo- λ 5 -diphosphenyl complex (μ 5 -C 5 Me 5 )(CO) 2 Fe-P(=S)=P-Ar (2). Heating of 2 in boiling benzene affords the metal functionalized thiadiphosphirane 3. Similarily the selenoxo-λ 5 -diphosphenyl complex (μ 5 -C 5 Me 5 )(CO) 2 Fe-P(=Se)=P-Ar (5) and selena-diphosphirane 6 are synthesized. The products have been characterized by elemental analysis as well as by spectroscopic data (IR, 1 H, 13 C, 31 P NMR, MS). The molecular structure of 2 has been elucidated by single crystal X-ray analysis.

Square-planar vinylidene rhodium complexes trans-[RhCl( = C=CHR)(PPr i 3 ) 2 ] (X-XII) are prepared either by isomerization of trans-[RhCl(RC≡CH)(PPr i 3 ) 2 ] in hexane at 50 °C or by elimination of pyridine from RhHCl(C≡CR)(py)(PPr i 3 ) 2 in benzene at room temperature. The Xray structural analysis of XI (R = CH 3 ) reveals that the CI-Rh=C=C fragment is almost linear, and that the planes formed by these atoms and C3 (carbon atom of the CH 3 substituent) and by these atoms and P1 , P2 are perpendicular to each other. The Rh = C bond length is surprisingly short (177.5(6) pm) and supports the assumption that vinylidenes like CO are strong π-acceptor ligands.

From the copper-catalyzed reaction of germanium powder with dichloromethane at 350 °C a mixture of alkylchlorogermanes is obtained, in which CH 3 GeCl 3 , CH 2 (GeCl 3 )2 (1) and (Cl 2 GeCH 2 ) 3 (2) are the major products. Treatment of 1 and 2 with LiAlH 4 in di-n-butyl or diethylether, resp., affords the hydrides CH 2 (GeH 3 ) 2 (3) and cyclic (H 2 GeCH 2 ) 3 (4), the latter along with the heterocycle H 2 Ge(CH 2 GeH 2 ) 2 (5). Compounds 3-5 have been identified by analytical and spectroscopic data, and the crystal structure of 4 has been determined by single crystal X-ray diffraction. The compound crystallizes in the orthorhombic space group Pmn2 1 , with two molecules in the unit cell (a = 8.663(1), b = 7.783(1), c = 6.124(1) Å). The molecules, which are in a chair conformation, have crystallographic mirror symmetry with bond angles slightly larger than tetrahedral and Ge-C distances of 1.944(6), 1.953(3) and 1.955(4) Å. The compounds show potential as substrates for plasma-enhanced chemical vapour deposition (PE-CVD) of amorphous germanium carbon alloys (a-Ge, C:H).

Dark, hydrophobic single crystals of Ca[C 6 (i-C 3 H 7 ) 2 O 4 H] 2· 2/3H 2 O were grown in aqueous silica gel. Infinite layers parallel to (001) formed by Ca 2+ and [C 6 (i-C 3 H 7 ) 2 O 4 H] - are the main feature of the crystal structure. Ca 2+ is coordinated in two different manners. Ca(1) has CN7: the coordination polyhedron is a slightly distorted capped trigonal antiprism made up by one water molecule and six oxygen atoms (O(1), O(2)) of the anions which chelate Ca(1). The mean Ca(1)-O distance is 238.9 pm. The coordination polyhedron of Ca(2) is a distorted octahedron formed by six anions acting as monodentate ligands via O(3): Ca(2)-O(3) 227.3 pm. In one half of the [C6(/-C3H7)204H] anion the bonding geometry resembles that of the corresponding dianions, but in the other half the bond lengths are very similar to those observed in free 2,5-dihydroxy-p-benzoquinones. The remaining H atom of the anion is involved in strong intramolecular hydrogen bonding as well as in an intermolecular hydrogen bond.

The bis(dimethylbismuth)alkanes (CH 3 ) 2 Bi(CH 2 ) n Bi(CH 3 ) 2 (n = 3, 4, 5) were prepared by reaction of NaBi(CH 3 ) 2 in liquid ammonia with dibromoalkanes Br(CH2)„Br (n = 3, 4, 5). Thermolysis of bis(dimethylbismuth)butane and bis(dimethylbismuth)pentane leads to the cyclic compounds 1-methyl-bismacyclopentane and 1-methyl-bismacyclohexane. Reaction of NaBi(CH 3 ) 2 with halogenomethyl(trimethyl)metallanes XCH 2 E(CH 3 ) 3 ( E = Si, Ge, Sn; X = Hal) produce compounds of the type (CH 3 ) 2 BiCH 2 E(CH 3 ) 3 .

Reaction of SbCl 3 with KPcp (Pep = pentamethylcyclopentadienyl) in etheral solution at -78 °C affords dimeric pentamethylcyclopentadiene and orange-red (PcpSb) 4 in high yield. 1 H, 13 C NMR, IR, UV and mass spectra are reported. The tetrameric structure was found by a crystal structure determination carried out with X-ray diffraction data collected at -50 °C (928 independent observed reflexions. R = 0.055). Crystal data: tetragonal, space group I4 1 /amd, a = 2400.0(5), c = 781.7(5) pm, Z = 4. The (PcpSb) 4 molecules have a non-planar Sb 4 ring with Sb -Sb bond lengths of 285.6(1) pm, one η 1 -Pcp ring is attached to each Sb atom. Contrary to the solid state structure, monomeric molecules are found in benzene and hexane solutions.

Ketenylidenetriphenylphosphorane complexes of the type L n MC(CO)PPh 3 L n M = CpMn(CO) 2 (2a), CpRe(CO) 2 (2b) and Fe(CO) 4 (3) are obtained by CO substitution reactions. The synthesis of 3 at 80 °C is accompanied by the formation of a Fe 2 (CO) 6 compound with a bridging α-metallated formyl(triphenylphosphane)carbido ligand. From ethylation of 3 arises an Fe 2 (CO) 6 ferrol-type complex 5.

The title compound 1 was prepared by cyclization of the dihydrobenzthiazole-acetic acid 6 and characterized by X-ray structure analysis.

From S,S-diorganosulfodiimides 1a-e with diphenylcyanimidocarbonate (2) via condensation products 3a-e and 6a-d novel heterocycles were obtained. In DMF 3a-c react with aliphatic amines to form 1λ 4 ,2,4,6-thiatriazines 4a-e and 5a, b. With HCl 6a-d can be cyclized to give 1λ 6 ,2,4,6-thiatriazine hydrochlorides 8a-d. These are thermally converted into 1λ 4 ,2,4,6-thiatriazines 4a, f, g. Condensation of 6a with orthoesters and paraformaldehyde affords 1λ 6 ,2,4,6- thiatriazines 9a, b and 10a, whereas 3a, e undergoes ring closure with methyl hydrazine to 1,2,4- triazoles 11a, e.

Three routes for the preparation of [1.4]diazepino[6.5-c]quinolines (1) have been studied. The best yields resulted by starting from the amides of N-(3-quinolylcarbonyl)-N-alkyl-amino acids (5). Quaternization to 9, intramolecular cyclization under the influence of base to 10, oxidation to 11 and debenzylation by catalytic hydrogenation gave 1.

Reaction of 3,3'-bipyridine with 1,3-dibromopropane, 1,4-dibromobutane, 1.5-dibromo-pentane, 1,6-dibromohexane. 1,7-dibromoheptane and 1.8-dibromooctane affords the corresponding bridged diquaternary salts, the structures of which were confirmed by fast atom bombardment mass spectrometry. Reaction with 1,2-bromoethane gives instead 1.1"-(1,2-ethanediyl)-bis-3.3'-bipyridinium dibromide.

4,7-Phenanthroline, Quaternary Salts, Dibromoalkanes 4,7-Phenanthroline reacts with dibromoalkanes to afford 4-bromoalkyl-4,7-phenanthrolinium bromides. 4-(3-Bromo-propyl)-and 4-(4-bromobutyl)-4,7-phenanthrolinium bromides on heat-ing afford the corresponding 4,4'-(alkanediyl)-bis-4,7-phenanthrolinium diquaternary salts whereas 4-(5-bromopentyl)-and 4-(6-bromohexyl)-4,7-phenanthrolinium bromides give the corresponding bridged diquaternary salts which are the first representatives of new heterocyclic ring systems.