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  • 1
    Electronic Resource
    Electronic Resource
    (β-Cyclodextrin)2·KI7·9 H2O. Spatial fitting of a polyiodide chain to a given matrix (1983)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 1 (1983), S. 181-191 
    Details
    ISSN: 1573-1111
    Keywords: (β-cyclodextrin)2·KI7·9H2O ; zigzag and linear polyiodide ; I2·I 3 − ·I2 ; starch-iodine model ; crystal structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract α-Cyclodextrin, a torus shaped molecule with a 5 Å wide central cavity, forms a number of deep green, blue and black crystals when complexed with iodine/metal iodide. In contrast, β-cyclodextrin, having a 6 Å cavity produces only one type of reddish-brown crystal, no matter what metal iodide is used. The complex (β-cyclodextrin)2 ·KI7·9H2O displays space groupP21 (pseudo-C2) with cell constantsa=19.609(5),b=24.513(7),c=15.795(6)Å, β=109.50(2)°,Z=4. The crystal structure was solved inC2 on the basis of 3022 absorption corrected CuKα (Ni-filter) X-ray intensities and refined by full matrix least squares toR=17%. This relatively highR-factor is due to many weak reflections (pseudo-C2) and considerable disorder exhibited by water and iodine. In the complex, β-cyclodextrin adopts a ‘round’ shape with O(2)...O(3) interglucose hydrogen bonds formed and all O(6) hydroxyls pointing away from the cavity. Two molecules are arranged head-to-head to produce a dimer, and dimers are stacked such that a slightly zigzagged cylinder with a 6 Å-wide cavity is formed. In the cavity described by each dimer, an I 7 − ion composed of I2·I 3 − ·I2 units is located, with I2 and I 3 − perpendicular to each other. K+ ions and 9 H2O molecules are found in interstices between the β-cyclodextrin cylinders. This zigzag polyiodide contrasts with the linear form observed in the 5 Å wide α-cyclodextrin channels. It explains differences in color of the crystals and suggests that β-cyclodextrin polyiodide is not a good model for blue starch-iodine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00656821
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  • 2
    Electronic Resource
    Electronic Resource
    Synthese und Reaktionen von (η51-Pentamethylcyclopentadienyl)1- und (η51-Ethyltetramethylcyclopentadienyl)titantrifluorid (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 913-919 
    Details
    ISSN: 0009-2940
    Keywords: Organometallic fluorides ; Titanium ; π1-Complexes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Preparation and Reactions of (η51-Pentamethylcyclopentadienyl)1- and (η51-Ethyltetramethylcyclopentadienyl)titanium Trifluoride[1]Compound Cp*TiCl3 (1, Cp*=η51-Me5C5) reacts with an excess of AsF3 to yield the crystalline complex [Cp*TiF3]2·2 AsF3 (2). AsF3 can be removed from 2 in vacuo to give Cp*TiF3 (3). Complex (η51-EtMe4C5)TiCl3 (4) is converted by an excess of AsF3 to (η51-EtMe4C5)TiF3 (5). Compound 3 reacts with a lithium 1,3-diketonate to form the hexacoordinated complex (6) and with a lithium benzamidinate to yield pentacoordinated Cp*TiF2[(Me3SiN)2 C-C6H4OMe-(4)] (7): The reaction of 3 with Ph3PNSiMe3 and C2H2(Ph2PNSiMe3)2 leads to Cp*TiF2NPPh3 (8) and (Cp*TiF2NPPh2)2C2H2 (9), respectively. X-Ray structure analyses of compounds 2 and 5-9 have been performed.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260410
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  • 3
    Electronic Resource
    Electronic Resource
    Addukt eines fünfgliedrigen Trischwefeldistickstoffdioxid-Rings an Titantetrachlorid (1990)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 123 (1990), S. 1345-1346 
    Details
    ISSN: 0009-2940
    Keywords: Sulphur-nitrogen ring ; Titanium ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Adduct of a Five-Membered Trisulfurdinitrogen Dioxide Ring with Titanium TetrachlorideReaction of S6N4O4 with TiCl4 lead to [(S3N2O2)TiCl4]2 (2). Single crystals of 2 were obtained by recrystallization from liquid SO2. 2 forms chains of five-membered S3N2O2 rings connected by Ti2Cl8 units. The S2N2 part of the five-membered ring may be described as a 6-π electron system.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19901230623
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  • 4
    Electronic Resource
    Electronic Resource
    Metallacyclodisiladiazanes of Titanium and zirconium; Synthesis, Structure and Polymerization Studies (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 399-404 
    Details
    ISSN: 0009-2940
    Keywords: Disilylamides ; Group 4 Complexes ; Polymerization ; Metallacycles ; Titanium ; Zirconium ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of metallacyclodisiladiazanes has been prepared. Lithiated (SiMe2NHtBu)2 (1) reacts with TiCl4 · 2 THF to give (SiMe2NtBu)2TiCl (4). Methylation or fluorination of 4 leads to (SiMe2NtBu)2TiMe2 (8) and (SiMe2MtBu)2TiF2 (9), respectively. The reaction of ZrCl4 · 2 THF with lithiated 1 or [SiMe2NH(4-FC6J4)]2 (2) yields (SiMe2NtBu)2ZrCl2 (5) and [SiMe2N(4-FC6H4)]ZrCl2 · THF (7), respectively. The lithiated ligand [SiMe2NH(2,6-iPr2C6H3)]2 (3) reacts with noncoordinated ZrCl4 to give [SiMe2N(2,6-iPr2C6H3)]2ZrCl2 (6). X-ray structural analysis of 9 showed it to be a fluorine-bridged dimer in the solid state. Compounds 4, 6, 8 and 9 were found to be catalysts for the polymerization of ethylene.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300314
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  • 5
    Electronic Resource
    Electronic Resource
    Preparation and Structural Investigations of (dippNSiMe3Si)2(Cp*Ti)2(NH)6 (dipp = 2,6-iPr2C6H3), [dippNSiMe3Si(NH2)NH]3 and [dippNSiMe3Ge(NH2)NH]3 (1999)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1999 (1999), S. 863-867 
    Details
    ISSN: 1434-1948
    Keywords: Germanium ; Nitrogen ; Silicon ; Titanium ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of dippNSiMe3Si(NH2)3 (1) (dipp = 2,6-iPr2C6H3) with Cp*TiMe3 (Cp* = C5Me5) and Me3SnCl yields the new heterocyclic adamantane (dippNSiMe3Si)2(Cp*Ti)2(NH)6 (2) containing the Si2Ti2(NH)6 core and the silicon-nitrogen six-membered ring compound [dippNSiMe3Si(NH2)NH]3 (4). [dippNSiMe3Ge(NH2)2]2NH (5) reacts with AlMe3 to give the germanium-nitrogen six-membered ring compound [dippNSiMe3Ge(NH2)NH]3 (6). The compounds 2, 4 and 6 have been structurally characterized by single-crystal X-ray structural analysis.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Thermochromic Furofurans. IV. Approach to the synthesis of bridgehead substituted furo[3,2-b]furans and side products of McMurry reactions (1996)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 338 (1996), S. 140-145 
    Details
    ISSN: 0941-1216
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Substituted dihydroxystilbenes 2 are suitable starting materials for the synthesis of photochromic systems derived from 3/4. Attempts to couple the naphthones 8a-8e by the McMurry reaction with TiCl3/LiAlH4 yielded mainly reduction products such as 8f, g or 9. However, the furofuran 3b was isolated when using the zinc-copper couple for reduction. The helicene 11 was formed as an unexpected by-product in the McMurry reaction of the pivaloylnaphthalene 8d.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19963380127
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  • 7
    Electronic Resource
    Electronic Resource
    Preparation of α-chiral crotylsilanes by retro-[1,4]-brook rearrangements. A stereochemical study (1995)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1995 (1995), S. 385-400 
    Details
    ISSN: 0947-3440
    Keywords: Asymmetric induction ; Diastereoselectivity ; 1,3-Diol ; Lithiation, reductive ; Rearrangement, retro-Brook ; Silane, α-chiral ; Silane, crotyl- ; Silane, γ-hydroxy- ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Treatment of alcohols cis-22, cis-23, and trans-23 with PPh3/ Ph2S2 provided three mixtures of isomers of α, γ-disubstituted allyl phenyl sulfides. They consisted of diastereomers and -except starting from trans-23-of regioisomers. Each mixture was lithiated reductively by lithium naphthalenide at -78°C in THF. α, γ-Disubstituted allyllithium compounds resulted which underwent retro-[1,4]-Brook rearrangements within 30-90 min. A high degree of stereocontrol by 1,3-asymmetric induction was observed in the rearrangement starting from a 5:1 mixture of the tBuPh2Si-containing sulfide regioisomers cis-25 and iso-25 (each regioisomer consisting of more than one diastereomer): The α-chiral crotylsilane anti, trans-26 was formed as a racemic mixture with ds = 93:7:0:0 in preference to isomer syn,trans-26 which possesses the opposite configuration at the silicon-bearing stereocenter and in preference to the corresponding cis isomers (Scheme 5). The rearrangements of the two other sulfide mixtures were much less stereoselective and exhibited ds = 49:44:4:3 starting from the two tBuPh2Si-containing diastereomers of the isomeric sulfide trans-25 (Scheme 5) and ds = 59:41 starting from the 3.5:1 mixture of the MePh2Si-containing sulfide regioisomers cis-24 and iso-24 (each regioisomer consisting of more than one diastereomer; Scheme 9). The stereostructures of the rearrangement products were determined by chemical correlations, NMR analogies, and a crystal structure analysis of 27. It was proven that the stereochemical outcome of the retro-[1,4]-Brook rearrangements of the MePh2Si-containing 3.5:1 mixture of sulfides cis-24/iso-24 is kinetically rather than thermodynamically controlled (Scheme 10). Mechanistic aspects are discussed in Schemes 11-13.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.199519950247
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  • 8
    Electronic Resource
    Electronic Resource
    Die Struktur des γ-Naphthocyclinons (1983)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1983 (1983), S. 503-509 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The structure of the γ-NaphthocyclinoneThe crystal structure of γ-naphthocyclinone (1) confirms the chemical and spectroscopic results and shows the configuration of the central bicyclo[3.2.1]octadienone ring to be 6′R, 8′S. The overall shape of 1 resembles a roof with a fold angle of 110° between the two halves of the molecule. The 6′-acetoxy group is situated above the chromophore next to the methylene bridge
    Notes: Die Kristallstruktur des γ-Naphthocyclinons (1) bestätigt die chemischen und spektroskopischen Befunde und weist die Konfiguration im zentralen Bicyclo[3.2.1]octadienon-System als 6′R, 8′S aus. 1 hat eine dachförmige Gestalt; der Winkel zwischen den Molekülhälften beträgt 110°. Die 6′-Acetoxygruppe steht über dem Chromophor in Nachbarschaft zur Methylenbrücke.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198319830314
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  • 9
    Electronic Resource
    Electronic Resource
    Neue Komplexe des Titans mit Bis(trimethylsilyl)amido-LigandenProfessor Kurt Dehnicke zum 60. Geburtstage gewidmet (1991)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 595 (1991), S. 21-26 
    Details
    ISSN: 0044-2313
    Keywords: Titanium complex compounds ; cyclopentadienyl titanium bis(trimethylsilyl)amido compounds ; syntheses ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Complexes of Titanium with Bis(trimethylsilyl)amido LigandsThe reaction of cp′TiCl3 with LiN(SiMe3)2 · Et2O 1 yield the compounds cp′TiCl2N(SiMe3)2 (cp′ = C5H5 2, C5H4SiMe3 3, C5H3(SiMe3)2 4, C5Me5 5) and cp′TiCl[N(SiMe3)2]2 (cp′ = C5H5 6). Compound 2 was characterized by an X-ray structural analysis with space group P21/n and unit cell dimensions of a = 1 660.9(7), b = 688.6(3), c = 1 739.1(8) pm and β = 117.18(3)°.
    Notes: Die Reaktion von cp′TiCl3 mit LiN(SiMe3)2 · Et2O 1 führt zu den Verbindungen cp′TiCl2N(SiMe3)2 (cp′ = C5H5 2, C5H4SiMe3 3, C5H3(SiMe3)2 4, C5Me5 5) und cp′TiCl[N(SiMe3)2]2 (cp′ = C5H5 6). Verbindung 2 wurde durch eine Einkristall Röntgenstrukturanalyse charakterisiert. 2 kristallisiert in der Raumgruppe P21/n mit a = 1 660,9(7), b = 688,6(3), c = 1 739,1(8) pm und β = 117,18(3)°.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19915950104
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  • 10
    Electronic Resource
    Electronic Resource
    Secondary Metabolites by Chemical Screening, 28. Aspinonene, a New Multifunctional Fungal Metabolite (1994)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1994 (1994), S. 831-835 
    Details
    ISSN: 0170-2041
    Keywords: Aspinonene ; Fungal metabolites ; Aspergillus ; Chemical screening ; Epoxides ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new C9 epoxide named aspinonene (1) was found by chemical screening in the culture broth of Aspergillus ochraceus (strain FH-A 6692). Its structure was deduced from spectroscopic data as well as from an X-ray analysis of the dibromobenzoate of 1. The configuration of C-2 was further verified by esterification of the ketone 4 with chiral acids (Helmchen's method). The reactivity of the functional groups was studied by acylation, silylation, ketalization, and oxidation. Due to the diversity of its functional groups and the neighbouring centres of chirality 1 is discussed as a secondary metabolite suited as a building block for synthesis.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.199419940812
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