Volume 38, Issue 4

The allyl iron complexes η 3 -C 3 H 5 Fe(NO)(CO)L (L = CN-, CNMe) can be obtained by the reaction of η 3 -C 3 H 5 Fe(NO)(CO) 2 with NaN(SiMe 3 ) 2 and subsequent methylation.

The anionic cyano nitrosyl manganates [Mn(NO)(CO) 3 CN] - and [Mn(NO) 3 CN] - are formed by the reactions of Mn(NO)(CO) 4 and Mn(NO) 3 CO with NaN(SiMe 3 ) 2 . The alkylation of these anions with [R 3 O]BF4 (R = Me, Et) leads to the corresponding isonitrile complexes Mn(NO)(CO) 3 CNR and Mn(NO) 3 CNR. IR, mass and 13 C NMR spectra indicate trigonal-bipyramidal coordination for nitrosyl tricarbonyl derivatives, with three CO ligands in facial positions and NO in the equatorial plane. Based on the temperature dependent 13 C NMR spectra of Mn(NO)(CO) 3 CNR and Mn(NO)(CO) 4 the fluctional behaviour of these compounds could be demonstrated with ⊿G+ values of 48 kJ/mol or less for the CO exchange.

The novel, strongly basic, tridentate P-N-ligands PhP(XC 5 H 4 N) 2 l a - c [X = CH 2 (a), O (b), NH (c)] are obtained between -60 and 0 °C by the action of PhPCl 2 on 2-picolyllithium, 2-hydroxy- and 2-aminopyridine, respectively, using NEt 3 and 2-aminopyridine as auxiliary bases, l a - c react with (OC) 3 M(NCCH 3 ) 3 to give the tricarbonyl-P-N-ligand complexes (OC) 3 M[PhP(XC 5 H 4 N) 2 ] 2 - 4 a - c [M = Cr (2), Mo (3), W (4)]. 4c crystallizes in the monoclinic space group P2i/n with Z = 4 and contains two five-membered, slightly distorted chelate rings.

The structure of the title compound has been determined by X-ray crystallography. The title compound is synthesized from the elements at 600 °C. Its crystal structure, derived from powder data [3] is refined by single crystal diffractometer data. The structure is trigonal (P3̅ml, α = 684.1(1), c = 724.4(1) pm); Pd 2+ cations and PS 4 3- anions form a network with an anti-Claudetite (AS 2 O 3 ) type structure. The PS 4 units are distinctly distorted from ideal tetrahedral symmetry. The Pd atoms have a planar environment of 4 S atoms.

The triorganyl-nonaphosphanes(3) P 9 (i-Pr)3 (1) and P 9 (t-Bu)3 (2) have been obtained by reacting (i-PrP) 4 with PCl 3 and by dehalogenating a mixture of t-BuPCl 2 and PCl 3 with magnesium, respectively. In the case of P 9 Et 3 (3) and P 9 Me 3 (4) the latter reaction may be modified by using the organyl-cyclophosphanes (PR) n instead of RPCl 2 . P 7 R 3 as well as other polycyclic organylphosphanes are formed as by-products. 1 could be isolated in pure form and 2 has been concentrated in the product mixture. According to their 31 P{ 1 H}-NMR spectra 1-4 possess a P 9 skeleton analogous to that of the hydrocarbon deltacyclane. 1 and 2 are formed as mixtures of two configurational isomers, which differ in the spatial arrangements of the substituent on P 5 . The results clearly indicate, that the corresponding phosphorus hydride P 9 H 3 has the same structure and is a tetracyclo[4.3.0.0 2,4 .0 3,7 ]nonaphosphane.

Decomposition of MeTl(OAc) 2 (Me = CH 3 , HO Ac = CH 3 COOH) in methanol in the presence of amines, like 2-, 3- and 4-picoline, benzylamines, dimethylaniline causes mainly N-methylation; the concurring O-methylation of acetate, giving MeOAc, is only of minor importance. The rate of N-methylation increases in the series 2-picoline ≤ pyridine < 3- picoline < 4-picoline ≤ dimethylaniline ≤ dimethylbenzylamine. Picolinic acid and MeTl(OAc) 2 (molar ratio 1:1) react to give 25% N-methylpicolinic acid and 75% MeOAc; when the molar ratio was at least 2:1, a 1:1 mixture of N-methylpicolinic acid and the methylester of picolinic acid was produced. These results and rate changes in different solvents are explained by assuming MeT10Ac + being the active methylthallium electrophile.

The complex [a,a′-dipyridyl(IN 3 ) 2 ] can be prepared by reaction of a,a′-dipyridyl with iodine azide in CH 2 CI 2 solution. It forms stable, yellow, moisture-sensitive crystals of melting point 73 °C. According to the IR spectrum the IN 3 molecules are covalently bonded to the N atoms of the dipyridyl via the iodine atoms. The crystal structure determination was carried out by X-ray methods (2127 independent reflexions, R = 3.2%). The complex crystallizes in the space group P2 1 /c with four formula units per unit cell, (a = 1299, b = 726, c -1647 pm; β = 96.1°). The IN 3 molecules form linear bridges N α -I-N to the nitrogen atoms of the pyridyl rings with bond lengths N α -I 217 pm and N pyr -I 244 pm. The dihedral angle of the pyridyl rings is 63.4°.

The oxidative addition of Br 2 to [PtCl 4 ] 2- in HBr yields almost pure trans-[PtCl 4 Br 2 ] 2- , in HCl nearly pure [PtCl 5 Br] 2- , and in CH 2 Cl 2 by a quantitative and stereospecific reaction completely pure trans-[PtCl 4 Br 2 ] 2- . This is confirmed by ion exchange chromatography on diethylaminoethyl cellulose and by analysis of the vibrational spectra in comparison with the IR and Raman spectra of the well-known species of the series [PtCl n Br 6-n ] 2- , n = 0-6. The literature concerning trans-[PtCl 4 Br 2 ] 2- and other mixed ligand complexes is critically discussed.

The photo-induced reaction between CpNb(CO) 4 and Ph 2 P(CH 2 ) 2 PR(CH 2 ) 2 PPh 2 (L; R = Ph, Cy) yields the chelated five-membered ring complexes cis-[CpNb(CO) 2 L] (two isomers in the case of R = Cy). The uncordinated PPh2 group reacts with CpNb(CO) 3 THF to form CpNb(CO) 2 (μ-L)CpNb(CO) 3 . IR, 31 P and 93 Nb NMR spectra are discussed and compared with corresponding data of the analogous vanadium complexes.

Di-and trithiocarbonate complexes of palladium(II) have been prepared by the action of O 2 or S 8 on PdL 2 (η 2 -CS 2 ) in the presence of excess L (L = phosphine ligand). 31 P NMR data for Pd(PPh 3 ) 2 (CS 2 O) are consistent with the presence in solution of both S̱,S̱ and S̱,O̱ coordinated dithiocarbonate. An X-ray crystal structure of the dichloromethane solvate [P1̄, a = 1103.6(4), b = 1343.4(5), c = 1368.5(5) pm, α = 94.77(3), β = 94.67(3), γ = 113.64(3)°, Z = 2, R = 0.059] suggests that an equivalent disorder may occur in the solid state.

The addition of CF 3 SCl (2) to the fluorinated nitriles R f CN[R f = CF 3 (3), NSF 2 (4), NSOF 2 (5)] leads to N-perfluoromethanesulphenyl-formylimidoylchlorides CF 3 S-N = C(Cl)R ƒ (6, 11, 12). From the reactions of SCl 2 (1) with (3) and (5), which yielded the N-sulphenyl-chlorides ClS-N = C(Cl)-R ƒ (7, 13), it proved possible also to isolate the oxidation product [CF 3 CCl 2 NSCl 2 (8)] and an oligomer of the nitrile [(NCNSOF 2 ) 3 (14)]. Dechlorination of 7 with Hg gives the corresponding di-and tri-sulphides (CF 3 C(Cl) = N-) 2 S x ; (9, 10, x =2, 3). Crystals of (14) are triclinic with a = 1133.6(5), b = 1332.6(5), c = 1715.1(8) pm, α = 109.31(3), β = 105.30(3), γ = 97.84(3)° at 170 K, Z = 8, space group P1̄. The structure was refined to R = 0.028 for 8290 diffractometer data with F > 4σ (F). The four crystallographically independent molecules adopt similar unsymmetrical conformations.

The reaction of N,N′-dimethyl-N,N′-bis(trimethylsilyl)urea with PCl 3 leads to the bicyclic compound OP 2 [MeNCONMe] 2 (3) with a direct phosphorus-phosphorus bond and to the bicycle MeNP 2 [MeNCONMe] 2 (4). 3 reacts with tetrachloro-o-benzoquinone (TOB) to yield the spirocycle Ce 6 Cl 4 tMeNCONMe] 2 P 2 O (5) with a λ 4 P-λ 5 P-bond. The Lewis acids SbCl 5 and SnCL 4 react with 3 to give the adducts 6 and 7. The reactions of 3 with the metal carbonyls Fe 2 (CO) 9 , Cr(CO) 5 THF and Cr(CO) 4 C 7 H 8 lead to the metal complexes 8-10. The compounds were characterized on the basis of 31 P NMR and mass spectra.

Crystals of the title compound are monoclinic, a= 18.9 93 (11), b = 8.757(5), c= 13.267(8) Å, β = 106.60(5)°, Z = 4 in space group Cc (C s 4 , No. 9). The structure was determined by Patterson and electron-density methods and refined by least squares techniques to R= 0.081, R′ = 0.085 for 1293 independent reflections classified as observed. The molecule is found to adopt an almost regular trigonal bipyramidal geometry in which the two biphenylylene units span apical-equatorial positions and the 2-thienyl group occupies the remaining equatorial site. The 2-thienyl group, which is disordered, does not lie in the equatorial plane, and there is no indication of C 2pπ → P 3dπ -t interactions between the heteroaryl group and phosphorus. The steric requirements of the 2-thienyl group appear to be comparable with those of methyl and phenyl groups in bis(2,2′-biphenylylene)spiro-phosphoranes.

The preparation of bis-hydroxophthalocyaninatoferrate(III) and of some of the bis-alkoxo-analogues is described. In the presence of a small excess of OR -(R = H, CH 3 , C 2 H 5 , (CH 3 ) 2 CH, (CH 3 ) 3 C) these complexes are stable in most common non-polar solvents and can be isolated as analytically pure bis-triphenylphosphiniminium-(PNP)-salts. Solutions of these complexes react immediately with water and acids. Thus hydrolysis is an easy way to prepare μ-oxo-bis-phthalocyaninatoiron(III). The reaction with mineral acids HX (X = F, Cl, Br, I) precipitates the pure pentacoordinated halogenophthalocyaninatoiron-(III). The electronic absorption spectra have been measured. Besides the typical inner-ligand π-π*-transitions additional bands are observed at ~11,5kK (CT1) and ~20kK (CT 2). These bands are of medium intensity only for FeXPc(-2) (X = Cl, Br, I) especially in the solid state spectra and are probably associated with ligand-to-metal-charge-transfer(CT)-transitions mainly of the Pc → Fe-type but partially mixed with X→Fe. CT 1 and CT2 are assigned to (a 1 ) π → (e,a 1 ) d respectively. This is confirmed by the resonance Raman spectra. On excitation within the range of the CT 2 electronic transition some in-plane stretching-(1595 and 1550 cm -1 ) and out-of-plane deformation vibrations (350 and 290 cm -1 ) of the macrocycle as well as the Fe-X-stretching vibrations are resonance Raman enhanced. Combination bands of Fe-X-with Pc-vibrations give strong evidence for coordination of the halide to an axial position of the iron centre. As expected for C 4 V point symmetry the Fe-X vibrations are IR active, too (ν(Fe-X) for X = F: 475; Cl: 303; Br: 221; I: 193 cm -1 ). The Fe-O stretching vibration (a 1g ) is only observed in the resonance Raman spectrum of PNP[Fe(OH) 2 Pc(-2)] at 495 cm -1 . As a consequence of the strong antiferromagnetic coupling the IR and resonance Raman spectra of (FePc(-2)) 2 O resemble those of closed shell ions. The IR absorption at 822 cm -1 is assigned to the anti-symmetric (a 2u ) (Fe-O-Fe) deformation mode.

The crystal and molecular structures of two isomers of bis(1-tert-butyl-2-methyl-η-1,2-azaborolinyl)cobalt have been determined by single-crystal X-ray diffraction methods. Isomer 1 shows a clockwise, isomer 2 an anti-clockwise conformation of the azaborolinyl rings. In both compounds the azaborolinyl rings have staggered orientations with opposite positions of the tert-butyl groups. The rings in 1 and 2 are slipped so that the three ring carbon atoms are closer to the cobalt atom than the BN groups. The staggered orientation of the ligands in 2 is probably due to a packing effect, as in similar sandwich complexes the anti-clockwise conformers show eclipsed orientation.

The synthesis of 3-methylenmonosubstituted-2-oxo-tetrahydrofurans 3 a-f from 3-phosphonolactones 1 a-b and the aldehyds 2a-d is described. 1 H NMR spectra of the 3-methylenmonosubstituted-2-oxo-tetrahydrofurans are discussed.

A stereospecific synthesis of 4,8-dimethylspiro(4,5)-deca-7-ene-1,6-dione from 4,7-dimethylcoumarine in high yield is reported. The configuration of this product is established according to its 1 H NMR and 13 C NMR data.

The He(I) photoelectron spectra of the five-membered and six-membered peroxylactones 1 and 2 have been recorded and are analyzed on the basis of MINDO/3 calculations. A strong destabilization of the peroxo η-combination due to the adjacent carbonyl group is found. In 2 the usual peroxide sequence (π_ on top of n_) is reversed.

Fulvenes (1) add ketenes (2) in a [ π 2 + π 2] manner to give bicyclo[3.2.0]heptenes (3). Ring cleavage with sodium methoxide yields dihydrofulvenes (4) which can be deliydrogenated to give fulvenes (5), whereas the acid catalyzed ring opening reaction of 3 leads to fulvenes (6). The structure of 3h has been clarified by X-ray crystallography.

From the culture medium of Pseudomonas putida after treatment with CH 2 N 2 besides the expected Pyridine-2,6-di(monothiocarboxylic acid)-di-S-methyl ester a series of pyridine derivatives could be isolated which could be shown to be artefacts formed from pyridine-2,6-di(monothiocarboxylic acid).

Facile syntheses of S 3 N 2 O, S 2 N 2 CO and S 4 N 2 from Ni(S 2 N 2 H) 2 are described.

The crystal structure of orthorhombic PbSO 3 (Pnma, Z = 4, a = 790.3(1), b = 548.8(1), c = 680.2(1) pm) has been determined using single crystal X-ray diffraction data (final R for 663 reflections with I ≥ 2σ(I) = 0.052). The parameters of the atoms in the asymmetric unit are: Pb(4c) 0.68444(8), 0.25, 0.36072(8); S(4c) 0.5362(5), 0.25, 0.8470(5); O 1 (4c) 0.686(2), 0.25, 0.981(2); O 2 (8d) 0.563(1), 0.471(2), 0.712(1). The sulfite ion has S-O distances of 149.4(7) and 153.7(5) (twice) pm. The Pb-O distances of the edge-connected Pb-O 7 polyhedra (distorted mono-capped trigonal prism) range from 253.4(5) to 284.8(5) pm. The structure is closely related to that of PbSO 4 .

The infrared and Raman spectra of the crystalline Ba 10 (ReO 5 ) 6 (NO 3 ) 2 apatite are reported and the vibrational properties of the NO 3 -ion present in this lattice are discussed in detail.

The hetero metal sulfur aggregates [Co(WS 4 ) 2 ] n- (with variable electron population: n = 2, 3) could be isolated as salts and characterized by physical measurements (in-cluding X-ray structure analysis). Experimental and theoretical investigations show that due to a strong metal → ligand electron delocalisation WS4 2- (like MOS 4 2- ) is a non-innocent ligand and that the additional charge upon reduction is located mainly at the S atoms of the ligand system.

The reaction of aniline with 2,3-O-isopropyldene-D-glyceraldehyde supplies the dimeric form of the expected Schiff's base which may serve as a model for the initial step of the Maillard reaction.

In boiling toluene 2-arylmethylperhydro- 1,5,2-dioxazones (1) undergo imidazole catalyzed ring transformation into 4-oxazolidinones (5) or decompose into glyoxylamides 4.

A new one step synthesis of β-carbolines is described, which involves the direct conversion of N-imidotryptamines to the corresponding lactams on reaction with P 2 S 5 .