Volume 40, Issue 10

The unstable parent compound of the sulfur diimides, S(NH) 2 (1), has been obtained in solution by stoichiometric protonation of the anion SN 2 2- in K 2 SN 2 with acetic acid. An analogous protonation of the salts S(NR)(NK) leads to the m onosubstituted sulfur diimides S(NR)(NH) containing bulky substituents such as R = tert-butyl (2) and R = trimethylsilyl (3); 2 and 3 can be isolated as white solids below -40 °C. The temperature-dependent 1 H NMR spectra of 1-3 indicate the presence of two isomers in solution (ratio 4:1) which are reversible interconverted.

The unstable parent compound of the sulfur diim ides, S(NH) 2 (1 ), and the labile monosubstituted sulfur diimides, S(NR)(NH) (R = tert-butyl (2) and trimethylsilyl (3)) react with the halfsandwich com plexes CpW (CO) 3 H (a) and Cp*W (CO) 3 H (b) under insertion into the W-H bond. The structures of the addition products (1a -3a, 1b -3b) are interpreted on the basis of a central four-membered metallocycle into which an acyl group and one of the N = S bonds are incorporated. The observation of two species in the 1 H and 13 C NMR spectra of 1a -3a and 2b, 3b is ascribed to interactions with the solvent.

The dinitrogen-tetrafluoroborato complex (Ph 3 P) 2 (Cl)(N 2 )(H)IrFBF 3 reacts with 9-m ethylguanine in CH 2 Cl 2 to give [(Ph 3 P) 2 (Cl)(H)Ir(9-methylguanine)] + BF 4 - (2). From a solution of 2 in methanol the complex (Ph 3 P) 2 (Cl) 2 (H)Ir(9-methylguanine) (3) is obtained. The reaction of [(Ph 3 P) 2 (Cl)(N 2 )(H)IrOSO 2 C 4 F 9 ] with 9-methylguanine affords the com plexes [(Ph 3 P) 2 (Cl)(N 2 )(H)Ir(9-methylguanine)] + C 4 F 9 SO 3 - (5) and [(Ph 3 P) 2 (Cl)(H 2 O)(H)Ir(9-methylguanine)] + C 4 F 9 SO 3 - (6). The coordination of the guanine derivative to the iridium atom in 2, 5, 6 is discussed on the basis of the infrared spectra. The crystal structure of 3 was determined. 9-Methylguanine is coordinated via N (7). Intermolecular hydrogen bonding between the chloro-ligand and HN (1) of guanine leads to linear chains in the crystal.

The chelate phosphanes Diphos, Diop, and Norphos were reacted with C 5 H 5 Mn(CO) 2 THF and CH 3 C 5 H 4 Mn(CO) 2 THF to give mononuclear complexes, containing the phosphanes as unidentate or as bidentate ligands, and dinuclear complexes, containing bridging phosphane ligands. In C 5 H 5 Mn(CO) 2 Diop one of the two P(C 6 H 5 ) 2 groups of Diop is coordinated to the C 5 H 5 Mn(CO) 2 fragment; the uncoordinated P(C 6 H 5 ) 2 group makes it a monodentate ligand. C 5 H 5 Mn(CO) 2 Diop together with [Rh(cod)Cl] 2 was used as an in situ catalyst in the enantioselective hydrogenation of (Z)-a-[N -acetam ino]cinnamic acid (78.4% ee) and in the enantioselective hydrosilylation of acetophenone with diphenylsilane (6.7% ee).

The phosphine complexes M-PH 3 (1), M-PH 2 Me (2). M-PH 2 Ph (3). and M-PH 2 /Bu (4) with M = Cr(CO) 5 . Mo(CO) 5 , W(CO) 5 , MnCp(CO) 2 . of which 2 and 4 were prepared for the first time, were reacted with Co 2 (CO) 8 . All four PH 3 complexes yielded the clusters M-PCo 3 (CO) 9 (5) with external M units as confirmed by a crystal structure determination of (CO) 5 W-PCo 3 (CO) 9 . Of the RPH 2 complexes 2 and 3 the chromium and tungsten compounds gave open trinuclear complexes of the type M-PRCo 2 (CO) 7 (6, R = Me: 7, R = Ph). The manganese containing complexes 2 and 3 and Co 2 (CO) 8 formed the dinuclear compounds Cp(CO) 2 Mn(μ-PRH)Co(CO) 3 (8d, R = Me; 9d, R = Ph). The molybdenum containing complexes 2 and 3 yielded unstable compounds of higher nuclearity with Co 2 (CO) 8 . The tBuPH 2 complexes 4 did not react.

The title compound 1 was prepared by reacting methyl-bis(dimethylamino)difluorophosphorane with butyllithium at -95 °C. The crystalline product is characterized by its NMR and IR spectra. The results of the X-ray crystal and molecular structure analyses are reported.

The complexes trans-[M(PR 3 ) 2 (SO)Cl] (M = Rh. Ir; R = isopropyl, cyclohexyl) were synthesized from [(C 8 H 14 ) 2 MCl] 2 , PR 3 and C 2 H 4 SO. The X-ray structure of [Ir(P/Pr 3 ) 2 (SO)Cl] shows the sulfur monoxide to be coordinated in a bent η 1 fashion. A bonding model is pro- posed which explains the similarity between SO- and SO 2 -complexes. Peracid oxidation trans- forms coordinated SO to SO 2 . CO displaces SO via isolable 5-coordinated intermediates [Ir(PR 3 ) 2 (CO)(SO)Cl].

The partially substituted cyclotriphosphane (t-BuP) 2 PH (1) has been obtained by hydrolysis of KP(t-BuP) 2 and by the reaction of (t-BuP) 2 PSiMe 3 with methanol, respectively. In contrast to the fully tert-butyl substituted cyclotriphosphane (t-BuP) 3 , 1 is not stable at room temperature, but decomposes favoring the rearrangement into the cyclotetraphosphane (t-BuP) 3 PH (2). The 31 P NMR parameters of 1 and 2 are reported and discussed.

By reaction of Zn(CH 3 COO) 2 ·2H 2 O. Cd(CH 3 COO) 2 -2H 2 O, or Hg(CH 3 COO) 2 with defined alcoholic polysulfide solutions the crystalline compounds (NEt 4 ) 2 [Hg(S 6 ) 2 ] (1), [(PPh 3 ) 2 N] 2 [Cd(S 6 ) 2 ]·CH 3 CN (2), (PPh 4 ) 2 [Zn(S 6 ) 2 ] (3) and (PPh 4 ) 2 [Hg(S 4 ) 2 ] (4) could be obtained. 1-4 were characterised spectroscopically (IR, Raman, UV/VIS) and by X-ray structure analyses.

The title compound, 1, is obtained as colorless crystals by reaction of LuCl 3 , NaC 5 H 5 and LiCH 3 in the molar ratio 1:1:4 in diethylether in the presence of tmed. 1 crystallizes in the tetragonal space group P4 1 2 1 2 1 a = 8.375(8) Å, c = 28.78(4) Å, V = 2018.6 Å 3 and Z = 4. The molecular structure of 1 possesses crystallographically imposed C 2 -symmetry and consists of a (C 5 H 5 ) 2 Lu-moiety joined to a Li(tmed)-unit by two methyl bridges. Principal dimensions are as follows: Lu-C (br) 2.461(12) Å, Li-C (br) 2.24(2) Å. Cp-Lu-Cp′ 131.9(3)°, C (br) -Lu-C′ (br) 95.0(3)°.

Hexaphenylcarbodiphosphorane Ph 3 P=C=PPh 3 (1) forms deeply coloured, crystalline 1:1 ad- ducts with elemental sulfur, selenium and tellurium (2, 3 and 7, respectively). A superior method of synthesis for 7 is the reaction of Na 2 Te with (Ph 3 P) 2 CCl ⊕ Cl ⊖ . All three compounds are thermally unstable and decompose at or below room temperature. A selenium adduct 5 was also obtained with Me 3 P = C = PPh, (4). The compounds 2 and 3 can be alkylated at the chalkogen atoms using MeOSO 2 F or PhCH 2 Cl. Oxydation of 3 leads to Se - Se coupling. Addition of elemental iodine to 1 in molar ratios 1:1. 2:3 and 1:2 affords salt-like products composed of the (Ph 2 P) 2 Cl ⊕ cation associated with I ⊖ and/or I 3 ⊖ anions (8a-c). The crystal and molecular structures of 3 and 8b have been determined by single crystal X-ray diffraction. 3′, containing one half equivalent of disordered tetrahydrofuran, crystallizes in the monoclinic space group P2 1 /n (a = 10.848(6), b = 17.433(8). c = 16.848(9) Å, β = 91.51(5)°. V = 3185.07 Å 3 , ϱ x = 1359 gcm -3 , Z = 4). Based on 3488 structure factors, the final R value was 0.103. The selenium is attached to the ylidic carbon atom without major changes of the Ph 3 P=C=PPh 3 skeleton (C - Se = 1.99 Å). 8b crystallizes in the triclinic space group P1̄ (a = 9.935(2). b = 11.507(2), c = 16.646(3) Å, α = 90.91(1), β = 112.00(1), γ = 96.60(1)°, V = 1749.15 A 3 , ϱ x = 1.741 gcm -3 , Z = 2). Refinement of 382 parameters on 5096 structure factors converged at R = 0.043. The molecular structure shows close similarities to the selenium adduct 3 (C-I = 2.12 Å).

Diluted solutions of potassium disilanyl, 2-potassium trisilanyl and 2-potassium isotetrasilanyl in m onoglym e have been prepared from potassium silyl and di- or trisilane under suitable reaction conditions. The purity of the silanyls varies between 95 and 99%. Their stability increases from potassium di- to 2-potassium isotetrasilanyl. The 29 Si NMR spectra exhibit a strong high field shift for the metal substituted silicon atoms and a m oderate low field shift for the other silicon atoms compared with the signals of the corresponding silanes.

31 P (and, as applicably, 77 Se) NMR spectra show P(CN) 2 - to take up one or two atoms of sulfur or selenium and to react with a variety of anionic phosphorus nucleophiles. Displacement of the first cyanide gives cyanodiphosphides, cyanophosphinidene-phosphates, -phosphinates, -thiophosphinates and -iminophosphinates, respectively. Displacement of the second cyanide gives triphosphates and triphosphinates which are otherwise known as products from the nucleophilic P 4 degradation.

Trithiazylchloride, (NSCl) 3 , reacts with metallic chromium, with chromium hexacarbonyl, with CrCl 3 ·3 thf, as well as with chromium(VI) oxide to form mixtures, in which S 4 N 3 ⊕ [CrCl 4 (N 2 S 2 )] ⊖ can be identified as the major product. This compound reacts with tetraphenylarsonium chloride in dichloromethane to form the title compound, which we have characterized by IR spectroscopy and an X-ray crystal structural analysis. (AsPh 4 ) 4 [CrCl 4 (N 2 S 2 )] 4 ·8 CH 2 Cl 2 crystallizes monoclinically in the space group C2/c with four formula units per unit cell and with the following lattice constants at -100 °C: a = 2146, b = 2033, c = 3137 pm; β = 96.0° (9918 independent observed reflexions, R = 0.064). The compound consists of AsPh 4 ⊕ ions, tetrameric anions [CrCl 4 (N 2 S 2 )] 4 4⊖ and included CH 2 Cl 2 molecules. The chromium atoms of the anions occupy the corners of a nearly ideal square; they are connected via the N-atoms of planar N 2 S 2 -rings, which are oriented perpendicularly to the Cr 4 -plane. The chromium atoms complete their distorted octahedral coordination with four terminal chlorine atoms, the axial ones of which form short Cl···S-contacts of average 310 pm to the S-atoms of the N 2 S 2 -rings.

Reaction of Me 2 SbBr or Et 2 SbBr with AgN 3 in ether affords Me 2 SbN 3 and Et : SbN 3 . respectively. Me 2 SbN 3 can also be obtained from Me 2 SbNMe 2 and HN 3 in ether. Me 2 BiN 3 from Me 2 BiN(SiMe 3 ) 3 and HN 3 in ether. Me 2 SbN 3 and Et 2 SbN 3 dissolve as monomers in benzene; 1 H, 13 C, ia N and 15 N NMR spectra of the solutions are reported. IR and Raman spectra of solid Me 2 SbN 3 and Et 2 SbN, as well as the mass spectrum of Me 2 SbN 3 are assigned. The crystal structures of Me 2 SbN 3 and Me 2 BiN 3 were determined by X-ray diffraction data collected at -67 °C (888 and 439 reflexions, R = 0.024 and 0.076. respectively). Both compounds are isotypic, space group Pnma. Z = 4. Crystal data: Me 2 SbN 3 , a = 843.6. b = 919.3, c = 744.1 pm: Me 2 BiN 3 , a - 870.8. b = 911.3, c = 738.4 pm. In the crystals, the metal atoms are linked via the aN atoms of the azido groups to form endless zig-zag chains. Whereas the Bi -N distances are equal. Sb-N bonds alternate with two different lengths (232 and 243 pm). Including the lone pair of electrons, the metal coordination can be described as distorted trigonal bipyramidal, with nitrogen atoms occupying the apical positions. With new X-ray diffraction data collected at -100 °C, the crystal structure of Me 3 PbN 3 was refined (1692 reflexions, R = 0.036). Crystal data: a = 656.3, c = 1377 pm. space group P3 2 21, Z = 3. It consists of endless metal-nitrogen chains of helical symmetry. the Pb atoms having trigonal bipyramidal coordination.

Pyridine-borabenzene (1) and pyridine-2-boranaphthalene (2) can be coordinated to group 6A metals M to form compounds of the type (OC) 3 M·1 and (OC) 3 M·2, respectively. X-ray structure determinations prove the ligands to be η 6 -bonded to the metal via the boron-containing six-membered ring.

The complex L 2 Rh(CO)Cl (3b) is obtained by reaction of [μ-ClRh(CO) 2 ) 2 (1) with L = Cl-[CH 2 ] 3 -P(C 6 H 11 ) 2 (2b) in benzene at 20 °C. 3b crystallizes in the triclinic space group P1 with Z = 1. On re fluxing 3 b in benzene an oxidative addition of one C-Cl bond to rhodium takes place to give the rhodacyclopentane derivative [xxx] (4b). Not only steric aspects of the ligands L and high electron density of the metal, but also free rotation about the Rh-P axis is important for the oxidative addition. Temperature dependent 31 P{ 1 H} NMR spectra of 3b between - 90 and 90 °C exhibit only one doublet in accordance with one rotameric form. Action of PMe 3 on [xxx] (4a) [L - Cl-[CH : ]; -P(C 6 HQ 2 (2a)] results in the formation of the cyclic acyl compound [xxx] (5a).

The hafnocene thiophenolates Cp 2 Hf(SC 6 H 4 R) 2 (Cp = η 5 -C 5 H s ; R = H, o-Me,p-Me, p-NH 2 ) and cis- 1.2-endithiolates Cp 2 Hf(S 2 C 6 H 4 ), Cp 2 Hf(S 2 C 6 H 3 Me-4), and Cp 2 Hf{S 2 C 2 (CN) 2 } were prepared by reaction of Cp 2 HfCl 2 with equivalent amounts of the appropriate lithium thiolates or endithiolates, or with Na 2 S 2 C 2 (CN) 2 . respectively. From variable temperature 1 H NMR studies of the endithiolate complexes with aromatic ligands a folded (“envelope”) conformation of the five-membered chelate rings, undergoing rapid inversion at room temperature, can be derived.

The crystal structure of the orthorhombic compound NMe 4 MnCr(CN) 6 -4H : 0 has been determined (a = 1496.5, b = 783.8, c = 1727.0 pm, space group Pnma. Z = 4, = 0.06 for 2018 independent reflections). The structure consists of puckered layers formed by Cr(CN) 6 3- octahedra (average Cr-C = 207.5 pm, C-N = 114.4 pm), which are two-dimensionally linked via cyano bridges Cr-CN-Mn to trans-dihydrated Mn(H 2 O) 2+ cations (Mn-O = 219.3 pm. Mn-N = 224.4 pm). Between the layers, which are separated by disordered tetramethylammonium ions and additional water molecules, a hydrogen bridge O-H···N is formed by two of the four terminal ligands. The structure found is intermediate between the framework arrangement of CsMnCr(CN) 6 and the chain structure of NMe 4 MnM(CN) 8 -8H 2 O. Some further relations are discussed.

The compounds Pd(PPh 3 ) 4 , Pt(PPh 3 ) 4 and Pt(PPr 3 i ) 2 react with CS 2 , CSSe and CSe 2 to give the mononuclear complexes (PR 3 ) 2 M(η 2 -CEE′). From Pd(PPh 3 ) 4 and excess CSe 2 the compound (PPh 3 ) 2 PdC 2 Se 4 is obtained. 1,2-C 2 H 4 (PPh 2 ) 2 (diphos) and 1,2-C 6 H 4 (CH 2 PPh 2 ) 2 (dpmb) react with (PR 3 ) 2 M(η 2 -CEE′) by ligand displacement to produce the chelate complexes (diphos)M(η 2 -CEE′) and (dpmb)M(η 2 -CEE′), respectively. The reaction of (PPh 3 ) 2 Pt(η 2 -COS) with diphos leads to the formation of the carbonyl compound (diphos)Pt(CO). In solution, the complexes (diphos)M(η 2 -CS 2 ) and (diphos)M(η 2 -CSe 2 ) slowly dimerise to form products of composition [(diphos)M(CEE′)] 2 which probably contain bridging CS 2 and CSe 2 units. (PPh 3 ) 2 Pd(η 2 -CSe 2 ) reacts with PMe 3 , PMe 2 Ph and PMePh 2 to produce the binuclear compounds [(PR 3 )Pd(Se 2 CPR 3 )] 2 in which the zwitterionic ligand PR 3 CSe 2 bridges the two Pd(PR 3 ) fragments. The analogous complexes [(PR 3 )Pd(SSeCPR 3 )] 2 are prepared from Pd(PR 3 ) 4 (PR 3 = PMe 3 , PMe 2 Ph, PMePh 2 ) and CSSe.

A series of novel alkyl or aryiimidovanadium(IV) 5,10,15,20-tetra(p-tolyl)porphyrinates, VNR(TTP) (4a-4g), is described. They are obtained from the vanadyl complex, VO(TTP) (2a) via the reactive intermediate VCl 2 (TTP) (3b) which undergoes aminolysis with the respective primary amines RNH 2 (R = tBu, Ph, pTol, pClPh, pAnis, pBiph, ptBuPh)**. The formulae are proved by elemental analyses and mass spectra. The paramagnetic complexes are stable to water and may thus be purified by chromatography but are hydrolyzed to give 2 a on treatment with acetic acid. The UV/VIS and 1 H NMR spectra of 4a-4g are of the same type as 2a, but the former are slightly hypsochromically shifted, and the latter do not show the proton resonances of the organylimide ligands due to the proximity of the paramagnetic metal center.

A new class of bimetallic isopropoxides of nickel(II) with niobium and tantalum with the general formula, Ni[M(OPr i ) 6 ] 2 , (where M = Nb or Ta) have been synthesized by the reaction of nickel chloride isopropanolate, NiCl 2 ·ϰPr i OH, with potassium hexaisopropoxy metalates, KM(OPr i ) 6 , (M = Nb or Ta) in the molar ratio 1:2. These derivatives have been characterized by elemental analyses, molecular weight determinations, infrared and visible reflectance spectroscopy in addition to magnetic susceptibility measurements. Alcohol interchange reactions of these bimetallic alkoxides have also been studied. On the basis of above studies, an octahedral geometry has been assigned to Ni(II) in primary bimetallic alkoxides while in secondary derivatives, it appears that there exists an equilibrium between octahedral and tetrahedral forms.

Anthracene and phenanthrene complexes of zerovalent cobalt, Co(Cl 4 H 10 )(PMe 3 ) 3 , are obtained by substitution of olefin in Co(olefin)(PMe 3 ) 3 (olefin = propene, cyclopentene). Ethene replaces the η 2 -bonded aromatic molecules. Substitution labile ligands L′ in hydridocobalt complexes CoH(L′)(PMe 3 ) 3 (L′ = N 2 , C 4 H 8 ) give way to an anthracene or phenanthrene ligand and can in turn be replaced by carbon monoxide. η 4 -Coordinated anthracene in Co[Sn(C 6 H 5 ) 3 ](C 14 H 10 )(PMe 3 ) 2 is not replaced by CO under normal conditions. In η 2 -coordinated anthracene the bond between coordinated C-atoms in ring positions 2 and 3 is elongated by 8.9 pm when compared with free anthracene, deviations from planarity of six-membered rings are slight. η 4 -Coordinated anthracene contains a naphthalin-type planar part and. in the coordinated ring with the longer CC-bonds, shows a folding away from the cobalt atom.

The synthesis of the SO- and SO 2 -complexes 3 and 4 follows equations (1) and (3) by nucleophilic substitution of SOCl 2 or SO 2 Cl 2 by the same metallate 2. 4 can also be obtained by simple air oxidation of solutions of 3 according to equation (2). Spectroscopic investigations indicate a trigonal bipyramidal configuration on iron with both phosphite ligands in axial positions and the sulfur oxide ligands in equatorial positions together with both carbonyl ligands. The X-ray structure analysis of the SO 2 complex 4 shows the exactly planar coordination of the sulfur atom and the nearly perpendicular orientation of the SO 2 plane to the equator plane; thus complex 4 is isolobal to SO 3 . The SO ligand in 3 coordinates as a 2c-2e-system in a bent structure with both atoms lying in the equatorial plane.

3,3′-Bicycloheptatrienylamidinium salts 3 have been prepared by oxidative dimerization of 8 ,8 -bis(dimethylamino)heptafulvene (1). An X-ray structure analysis of the meso-octamethyl[bi-2,4,6-cycloheptatrienyl]3,3'-dicarboxamidinium-bis(triiodide) (3b) has been carried out. The dication 3 is centrosymmetric (C i -symmetry) with boat shaped cycloheptatriene rings. The amidinium groups are twisted out of the plane of the C3(C3′)-C2(C2′) double bonds. The structure of the dication in the solid state is discussed in comparison with the structure in solution by aid of 1 H NMR techniques. The N-methyls within one amidinium group show temperature dependent 1 H NMR spectra and are chemically nonequivalent (anisochronous).

Hydride supported alloys Mg 2 Ni (A), CaNi 5 (B) and FeTi (C) are in contrast to Ra-Ni unable for the catalytic hydrogenation and the hydrogenolysis of sulfur compounds. The origin and quality of the “structure bonded hydrogen” in Ra-Ni is still speculative.

The chemical structure of 5 different products of pyridostigmine obtained by reduction with NaBH 4 was determined by GC-MS and subsequently confirmed by means of 1 H and 13 C NMR spectroscopy. Reaction conditions leading almost exclusively to the main product: 3-[(N,N-dimethyl)-carbamoyl]-1-m ethyl-1,2,5,6-tetrahydropyridine (4) have been determined.

Ester and amides of N-(3-quinolinecarbonyl)-N-methyl-phenylglycine (4) cyclise under the influence of base to derivatives of pyrrolo-quinolines (6-9, 11). Tetracyclic products (10) are formed in the reaction of 4 with ammonia.

The relationship between net charges and 1 H chemical shifts in cyclic conjugated charged hydrocarbons is investigated by taking into account explicitely ring current and local anisotropic contributions and the effect of ion-pairing.

The title compound is formed from [Hg(η 1 -dppm) 2 ](O 3 SCF 3 ) 2 and dppm, and is fluxional on the NMR time scale as the result of fast intramolecular displacement of coordinated phosphorus by free phosphorus in the η 1 -dppm ligands; at temperatures above 253 K intermolecular ligand exchange sets in.