Showing papers by "George M. Sheldrick published in 1986"
TL;DR: The crystal structure of the 2-PhNNC6H4)Au(2-C6H 4CH2NMe2)][AuCl4] has been determined by metathesis between the corresponding perchlorate and tetramethylammonium salts as mentioned in this paper.
47 citations
TL;DR: In this article, the structure of the complex (C6F5)ClAu(dppa)AuCl(C6Fs5) has been determined by single-crystal X-ray diffraction: space group C2/c, a= 18.009(3), b= 17.033(2), c=18.420(3)
Abstract: Addition of bis(diphenylphosphino)amine (dppa) to neutral or cationic gold(I) and gold(III) complexes containing weakly co-ordinating neutral ligands leads to the formation of complexes of the following types: [RAu(dppa)AuR], [Au2(dppa)2][ClO4]2, [AuR3(dppa)], and [AuR2Cl(dppa)](R = C6F6 or C6Cl5). Oxidative-addition of halogens X2(X = Cl or Br) to the gold(I) complexes leads to the gold(II) derivatives [RXAu(dppa)AuXR] and [XAu(dppa)2AuX][ClO4]2 which can be further arylated with Ag(C6F5) to give [R2Au(dppa)AuR2] and [RAu(dppa)AuR][ClO4]2. Mixed gold(III)–gold(I) derivatives can also be synthesized either by the spontaneous isomerization of the gold(II) complexes or from mononuclear gold(III) derivatives. The structure of the complex [(C6F5)ClAu(dppa)AuCl(C6F5)] has been determined by single-crystal X-ray diffraction: space group C2/c, a= 18.009(3), b= 17.033(2), c= 18.420(3)A, β= 103.79(2)°, Z= 4, and R= 0.035 for 4 000 unique observed reflections. The molecule possesses crystallographic two-fold symmetry, with Au–Au 2.576(2)A; this is the shortest reported Au–Au bond. The unit cell also contains eight di-isopropyl ether and four water molecules, which are well ordered and form a hydrogen bonding network with the amine N-H group.
44 citations
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TL;DR: AuCl(CH2PR3) as discussed by the authors gives neutral tetranuclear derivatives, ring systems in which the amido or methanido ligands are tridentate (confirmed by X-ray structures of two products).
Abstract: Deprotonation of bis(diphenylphosphino)amine or bis(diphenylphosphino)methane with [AuCl(CH2PR3)] leads to neutral complexes [X(Ph2PAuPPh2)2X](X = N or CH) that react further with [Au(C6F5)(tht)](tht = tetrahydrothiophene) or [Ag(OClO3)(PPh3)], giving neutral tetranuclear derivatives, ring systems in which the amido or methanido ligands are tridentate (confirmed by X-ray structures of two products).
38 citations
37 citations
TL;DR: In this paper, the crystal structure of [Au(dmp)(phen)(PPh3)][BF4]2·CH2Cl2 shows a distorted square-pyramidal co-ordination, with the basal plane containing Au and the donor atoms of dmp, PPh3, and one phen N atom; the other N atom occupies a more distant axial position.
Abstract: Complexes [Au(dmp)(phen)]X2[dmp = 2-(dimethylaminomethyl)phenyl, phen = 1,10-phenanthroline, X = BF4 or ClO4] react (i) with PR3(R = Ph or C6H4OMe-p)(1:1) to give the five-co-ordinated complexes [Au(dmp)(phen)(PR3)][BF4]2, (ii) with KCN (1:1) to give [Au(dmp)(CN)(phen)]BF4, and (iii) with KCN and 1,2-bis(diphenylphosphino)ethane (dppe) to give [Au(dmp)(CN)(dppe)]ClO4, which in turn reacts with [AuCl(tht)](tht = tetrahydrothiophene) to form the gold(I)–gold(III) complex [Au(dmp)(CN)(dppe)AuCl]ClO4. Complexes [Au(dmp)(py)2]X2(py = pyridine) react with 8-hydroxyquinoline (NC9H6OH) or 2-aminothiophenol (H2NC6H4SH) to form [A[graphic omitted])]BF4 or [A[graphic omitted])]ClO4 respectively; the crystal structures of these latter complexes show square-planar co-ordination of the gold atom with the phenyl group of dmp trans to oxygen or nitrogen respectively. The crystal structure of [Au(dmp)(phen)(PPh3)][BF4]2·CH2Cl2 shows a distorted square-pyramidal co-ordination, with the basal plane containing Au and the donor atoms of dmp, PPh3, and one phen N atom; the other N atom occupies a more distant axial position [Au–N 2.151(12), 2.154(8), and 2.627(10)A].
34 citations
24 citations
TL;DR: In this article, a monodentate o-nitrophenyl group was shown to have a longer N-O bond length than the uncoordinated one, and showed no significant differences in the bond lengths Pt-C and N-C.
Abstract: Reaction of [Hg(o-C6H4NO2)2] with K2[PtCl4] or PtCl2(2 : 1) yields the complex [P[graphic omitted]}2]. It reacts (i) with monodentate ligands L (PPh3, AsPh3, or pyridine)(1 : 1) to give complexes of the type [[graphic omitted]}(o-C6H4NO2)L] or (ii) with monodentate L (PPh3, AsPh3, pyridine, or CO)(1 : 2) or bidentate ligands L2[cyclo-octa-1, 5-diene, 1,10-phenanthroline, 2, 2′-bipyridine, 1, 2-bis(diphenylphosphino)ethane, or bis(diphenylphosphino)methane](1 : 1) to give complexes [Pt(o-C6H4NO2)2L2]. The crystal structure of [[graphic omitted]}(o-C6H4NO2)(PPh3)] shows both chelating and monodentate o-nitrophenyl groups. They show no significant differences in the bond lengths Pt–C [2.018(9) and 1.983(8)A, respectively] and N–C [1.446(11) and 1.468(12)A, respectively]. The co-ordinated oxygen atom has a longer N–O bond length [1.273(10)A] than the unco-ordinated one [1.221(10)], cf. those in the unco-ordinated o-nitrophenyl group [1.220(10) and 1.230(11)A].
19 citations
TL;DR: (Z )-anti-4-hydroxy-1-alkenyl carbamates 1 yield, with essentially complete diastereoselectivity, for the epoxides 2 with (1 Z -2-3- anti-3, 4, 4 anti-configuration on treatment with tert -butylhydroperoxide/vanadylbis(acetoacetonate) as mentioned in this paper.
18 citations
TL;DR: The crystal structures of three compounds containing eight-membered Si4(N,O)4 rings have been determined: [t-Bu2SiOSiMe2O]2 (I), [t -BuSiOSIMe2NH]2(II) and [i-Pr2SiNH]4 (III) as mentioned in this paper.
TL;DR: The reaction of 1,2,5-selenadiazoles 2 and 4 and the bicycle 6 with (η2-ethene)bis(triphenylphosphane)platinum(0) leads to the cyclic coordination compounds (Ph3P)2PtSeN2(CR)2 (R = CN, 3; R = OCH2CF3, 5) and dem Bicyclus (Ph 3P) 2PtC4Cl2N4S3 (7) as discussed by the authors.
Abstract: Die Reaktion der 1,2,5-Selenadiazole 2 und 4 sowie des Bicyclus 6 mit (η2-Ethen)bis(triphenylphosphan)platin(0) fuhrt zu den cyclischen Koordinationsverbindungen (Ph3P)2-PtSeN2(CR)2 (R = CN, 3; R = OCH2CF3, 5) und dem Bicyclus (Ph3P)2PtC4Cl2N4S3 (7). Von 3 wurde eine Rontgenstrukturanalyse angefertigt, die das Vorliegen eines sechsgliedrigen Ringes bestatigt.
Preparation and Structure of New Six-membered Metallaheterocycles – Insertion of Platinum in Selenium-Nitrogen and Sulfur-Nitrogen Bonds
The reaction of 1,2,5-selenadiazoles 2 and 4 and the bicycle 6 with (η2-ethene)bis(triphenylphosphane)platinum(0) leads to the cyclic coordination compounds (Ph3P)2PtSeN2(CR)2 (R = CN, 3; R = OCH2CF3, 5) and the bicycle (Ph3P)2PtC4Cl2N4S3 (7). The structure of 3 was determined by an X-ray structure analysis.
TL;DR: In this paper, the X-ray structure analysis of 5, 7, and 8 is reported, where the bicyclic fragment present in 7 is also formed from PhP(CN)2 and HFA.
Abstract: Aus Hg(SCN)2 wird mit Hexafluoraceton (HFA) das Cycloadditionsprodukt 1 erhalten. Dieses reagiert mit CF3SCl, ClSC2F4SCl und Br2 unter Eliminierung des Quecksilbers zu den Disulfanen 2,3 und 4. Aus 1 und Ph2PCl entsteht das bicyclische Phosphoran 5. Hg(CN)2, HFA und Ph2PCl reagieren zu 7. Die gleichen bicyclischen Strukturelemente, wie sie in 7 vorliegen, werden auch in 8, dem Reaktionsprodukt aus PhP(CN)2 und HFA, gefunden. Die Rontgenstrukturanalysen von 5, 7 und 8 werden mitgeteilt.
Synthesis and Structures of Bicyclic Phosphoranes — Products Resulting from the Reaction of Hexafluoroacetone with Mercury Salts
Hg(SCN)2 reacts with hexafluoroacetone (HFA) to give the cycloaddition product 1. Reaction of 1 with CF3SCl, ClSC2F4SCl, and Br2 leads to elimination of mercury with formation of the disulfanes 2,3, and 4, respectively. 1 reacts with Ph2PCl to yield the bicyclic phosphorane 5. The reaction of Hg(CN)2 with HFA and Ph2PCl leads to 7. The bicyclic fragment present in 7 is also found in 8, which is formed from PhP(CN)2 and HFA. The X-ray structure analysis of 5, 7, and 8 are reported.
TL;DR: Govindachari et al. as mentioned in this paper showed that cyclosilazane lL9] was heated in n-hexanel dichloromethane (10:3 v/v), and a phase separation was observed upon cooling the mixture.
Abstract: [ I ] a) T. R. Govindachari, P. C. Parthasarathy, Tetrahedron 27 (1971) 1013; b) T. R. Govindachari, K. Nagarajan, P. C. Parthasarathy, T. G. Rajagopalan, H. K. Desai, G. Kartha, S. Lai Chen, K. Nakanishi, J . Chem. Soc. Perkin Trans. I 1974. 1413. I 4 M. Shamma: The Isoquinoline Alkaloids. Academic Press, New York 1972, p. 501. 131 Reviews: a) T. R. Govindachari, P. C. Parthasarathy, Heterocycles 7 (1977) 661; b) G. Bringmann (The Naphthyl Isoquinoline Alkaloids) in A. Brossi (Ed.): The Alkaloids. Vol. 29, Academic Press, New York, in press, p. 14 1 : c) in: 3S Jakre Fonds der Ckemischen Industrie. 1950-1985, Verband der Chemischen Industrie, Frankfurt 1985, p. 151. [4] G. Bringmann, J. R. Jansen, Tetrahedron Lett. 25 (1984) 2537. [ S ] For syntheses of arylpropanones, see a) S. Ahmad, W. B. Whalley, D. F. Jones, J . Chem. Soc. C1971, 3590; b) H. B. Has , A. G. Susie, R. L. Heider, J . Org. Chem. I5 (1950) 8. [6] G. Bringmann, J. R. Jansen, Heterocycles 24 (1986) 2407. [7] G. Bringmann, Liebigs Ann Chem. 1985. 2126. [8] a) F. Weinges, G. Graab, Chem. Ztg. 94 (1970) 728; b) D. E. Nichols, C. F. Barfknecht, D. B. Rusterholz, J . Med. Chem. 16 (1973) 480; c) G. . rarely exhibits basic properties ;1i.21 adducts-which frequently undergo further reaction and consequently cannot be isolated-are formed only with very strong Lewis acids. Protonated silazanes have, to out knowledge, never been detected so far. Hitherto, there have been two major objectives on carrying out reactions of aluminum trihalides with silazanes: First, the synthesis of aluminum ~ilazanes,[3-~] and second, the synthesis of compounds with threefold coordinated silicon.‘6-81 The stabilization of silicon ylides by adduct formation with aluminum trihalides1’1 motivated us into investigating reactions of cyclosilazanes with AI,CI,. When the cyclosilazane lL9] was heated in n-hexanel dichloromethane (10:3 v/v), a phase separation was observed upon cooling the mixture. Evaporation of the dichloromethane phase to dryness furnished the salts 2 Knupp, A. W. Frahm, Arch. Pharm. (Weinheim. Ger.1318 (1985) 535, and references cited therein. I91 Not only 1 but, in fact, all naphthyl isoquinoline alkaloids whose structures have been elucidated unequivocally exhibit the (S) configuration at C-3 of the isoquinoline moiety. Cf. 131.
TL;DR: In this paper, the decomposition and trimerisation of (CF3)2 NOSN (2) are investigated, the structure determinations of 2 (by electron diffraction in the gas phase) and of [(CF3]2 NOSN]3 (6) (by x-ray crystallography) are reported.
TL;DR: The acid-catalyzed ring opening of the title epoxide 1 takes place at the C-1 atom with retention of configuration at C-2 to form 2,3- cis -2-hydroxy-substituted γ-lactol derivatives as mentioned in this paper.
TL;DR: In this paper, the structure of [Au(C6F5)(Ph2PCHPPh2Me)] has been determined by X-ray diffraction [space group P, a= 8.888(2), b= 13.053(3), c= 14.230(4)A, α= 103.15(2)
Abstract: The precursors [AuRm(Ph2PCH2PPh2Me)]ClO4(Rm= one or three uninegative ligands) react with excess of NaH by deprotonation of the methylene group and simultaneous elimination of the ClO4 anion to give the neutral methanide complexes [AuRm(Ph2PCHPPh2Me)], which are potential C-donor ligands; these react with complexes of AuI, AuIII, or AgI to form di- or tri-nuclear derivatives of the types [RmAu{Ph2PCH(PPh2Me)}AuX](X = Cl or C6F5), [{(C6F5)AuPh2PCH(PPh2Me)}2M]X (M = Au or Ag; X = AuCl2 or ClO4), or [(C6F5)Au{Ph2PCH(PPh2Me)}Au(C6F5)3]. The structure of [Au(C6F5)(Ph2PCHPPh2Me)] has been determined by X-ray diffraction [space group P, a= 8.888(2), b= 13.053(3), c= 14.230(4)A, α= 103.15(2), β= 107.22(2), γ= 102.28(2)°, R= 0.026 for 4 806 reflections], as has that of [(C6F5)Au{Ph2P[graphic omitted]u(C6F5)][space group P21/n, a= 12.127(3), b= 22.758(6), c= 13.433(3)A, β= 98.97(2)°, R= 0.051 for 4 798 reflections]. In the methanide moieties the P–C bond lengths are much longer, and the P–C–P angles much smaller, in the latter compound, reflecting the reduced electron delocalisation in the P–C–P system when the methanide C functions as a donor ligand.
TL;DR: The octaruthenium species [Ru 8 (μ 8 -P)(μ 2 -η 1,η 6 -CH 2 C 6 H 5 )(μ 2 −CO) 2 (CO) 17 ] as discussed by the authors ] is a compound that is composed of a phosphorus atom encapsulated in a square anti-prism, and a benzyl group is coordinated to two of these ruthensium atoms through all seven carbon atoms.
TL;DR: The complexes [Ru3(CO)7(NPh)(C6H6) as mentioned in this paper and [FeCo2(CO), 9(N Ph)] are formed in the reactions between PhNO2 and [M3(Co)12] only when [Co2[Co] is present.
Abstract: The complexes [Ru3(CO)7(NPh)(C6H6)](1) and [FeCo2(CO)9(NPh)](2) are formed in the reactions between PhNO2 and [M3(CO)12](M = Ru or Fe) only when [Co2(CO)8] is present. The structure of (1) has been determined by X-ray diffraction; it contains triply bridging CO and PhN ligands and an η6-benzene ligand co-ordinated to only one metal atom.
TL;DR: In this article, the tetrametallic title complex has been solved by X-ray diffraction methods and the crystal structure of the title complex was discussed on the basis of 1H and 19F n.r. data.
Abstract: The complexes [{[Pd2{µ-C(C6F5)NR1}2](µ-X1)(µ-X2)}n](R1= Me or p-tolyl; X1= X2= Cl) and their derivatives (X1= Cl, X2= MeCO2 or CF3CO2; X1= X2= MeCO2 or CF3CO2), obtained by metathetical reactions with the corresponding silver salts, are shown to be tetrametallic (n= 2) by molecularweight determinations. Their structures are discussed on the basis of 1H and 19F n.m.r. data. The crystal structure of the title complex has been solved by X-ray diffraction methods [space group P21/n, a= 14.380(4), b= 19.980(4), c= 15.976(4)A, β= 103.51(3)°, Z= 4, R′= 0.046 for 5 428 unique observed reflections]. The tetrametallic molecule is crown-shaped. The bond lengths at palladium reflect the strong trans influence of the imidoyl-C atom; the Pd–Cl bonds trans to C are amongst the longest known.
TL;DR: The diazidodithiophophosphate anion [PS₂(N₃)µ)₁₻] can be isolated with a large cation as (Ph₄Asµ] [PSµ(N₵)³₾₽₿µ as mentioned in this paper, which is formed by the reaction of P₆S₀ with NaNµ in acetonitrile as a solvent.
Abstract: The diazidodithiophosphate anion [PS₂(N₃)₂⁻] can be isolated with a large cation as (Ph₄As⁺][PS₂(N₃)₂⁻] (1). [PS₂(N₃)₂⁻] is formed by the reaction of P₄S₁₀ with NaN₃ in acetonitrile as a solvent. [(NCPS₂)₂S₂⁻] results from the reaction of P₄S₁₀ with NaCN in acetonitrile and is isolated as [(n-C₃H₇)₄N⁺H(NCPS₂)₂S²⁻] (2). 1 crystallizes in the triclinic space group P1 with a - 1329.3(3), b = 1419.1(3),c = 2182.3(5) pm, α = 71.71(2), β = 87.21(2), γ = 84.97(2)° and Z = 6. Crystals of 2 are monoclinic, space group P2₁/n, a - 1899.0(3), b - 949.0(2), c = 2128.4(5) pm, β = 112.90(2)°, Z = 4.
TL;DR: In this paper, the reaction between 1,2,4,thiadiazol-3,5-dicarbonitrile, S(CN)₄, and sulfur chlorides (SCl₂) in the presence of Adogen® 464 (Aldrich) was characterized by X-ray structure determination of an adduct 1a and of 2.
Abstract: The reactions between 1,2,4-thiadiazol-3,5-dicarbonitrile, S(CN)₄, and sulfur chlorides (SCl₂ and S₂Cl₂) in the presence of Adogen® 464 (Aldrich) proceeds with formation of S₃(CN)₄Cl₂ (1) and S₃(CN)₈Cl₂ (2). These main products were characterized by X-ray structure determination of an adduct 1a and of 2. This adduct 1a was obtained by addition of the Lewis acid AsF₅ in liquid SO₂. 1a crystallizes with one SO₂ molecule in the space group P2₁/n with a = 1177.3(2), b = 1082.8(1), c = 1255.3(5) pm, β = 109.73(3)°, Z = 4, V = 1.5061 nm³. It contains two five-membered rings connected by a nitrogen atom. AsF₅ is coordinated to one of the ring nitrogen atoms [N(1)] adjacent to the sulfur atom S(1) and C(1)Cl-group. The other ring contains an S(2)-S(3) bond of length 207.7(4) pm. The rings are planar within experimental error. 2 crystallizes in the space group P2₁/n with a = 782.12(6), b = 1498.1(5), c = 1217.8(2) pm, β = 102.43(1)°, Z = 4, V = 1.3934 nm³. 2 is formed by addition of one molecule of SCl₂ to two molecules of S(CN)₄.
TL;DR: In this article, the X-ray structure analysis of 3a, an acetonitrile adduct of 3, is reported, and the reaction of the title compound (CF3)2CC(CN)2 with PCl5 the (phosphoranyliden-amino)ethene 1 is obtained.
Abstract: Die Titelverbindung (CF3)2CC(CN)2 reagiert mit PCl5 zu dem (Phosphoranylidenamino)-ethen 1. Daraus entsteht 2 durch Reaktion mit Me3SiNMe2. Umsetzungen von (CF3)2CC(CN)2 mit WCl6 und MoCl5 ergeben die acyclischen Nitrenkomplexe 3 und 4. Von 3a, einem Acetonitriladdukt von 3, wird eine Rontgenstrukturanalyse mitgeteilt.
Addition Reactions of 1,1-Dicyano-2,2-bis(trifluoromethyl)ethene
By the reaction of the title compound (CF3)2CC(CN)2 with PCl5 the (phosphoranyliden-amino)ethene 1 is obtained. The phosphorane 1 reacts with Me3SiNMe2 to form 2. WCl6 and MoCl5 react with (CF3)2CC(CN)2 to give the acyclic nitrenes 3 and 4. The X-ray structure analysis of 3a, an acetonitrile adduct of 3, is reported.
TL;DR: The functionalized dispiro [2.1.3.3] undecanes 9 and 8 undergo cascade rearrangements to yield the bi-and tricyclic systems 10, 11, 12 and 3, respectively.
Journal Article•
TL;DR: In this paper, a crystal structure determination of [WF4L2][space group Fdd2, a= 33.832(8), b= 18.933(4), c= 9.926(2)A, Z= 8; R= 0.021] showed it was the cis isomer with crystallographic 2 symmetry.
Abstract: The complexes [WF5L] and [WF4L2](L = Ph3PN) have been prepared from WF6 and LSiMe3; they are crystalline solids with high kinetic stability. A crystal structure determination of [WF4L2][space group Fdd2, a= 33.832(8), b= 18.933(4), c= 9.926(2)A, Z= 8; R= 0.021] showed it to be the cis isomer with crystallographic 2 symmetry. The W–N bond length of 1.825 A suggests multiplebond character. There is appreciable deviation from linearity at nitrogen (W–N–P 157.2°).