Structures and photochemistry of 1,5-disubstituted dibenzobarrelenes

1996 ◽  
Vol 52 (1) ◽  
pp. 151-158
Author(s):  
R. Jones ◽  
S. J. Rettig ◽  
J. R. Scheffer ◽  
J. Trotter ◽  
J. Yang
Keyword(s):  
Crystal Structure ◽  
Double Bond ◽  
Crystal Structures ◽  
Structure Analysis ◽  
Crystal Structure Analysis ◽  
The Other ◽  
Steric Effects ◽  
Molecular And Crystal Structures ◽  
Electronic And Steric Effects

The effect of 1,5-disubstitution on the photochemistry of 9,10-ethenoanthracene-11,12-diesters has been studied and correlated with the crystal structures determined for several derivatives; photoproduct structures have been established from a crystal structure analysis of one of the products and from NMR correlations. The crystals studied are: (1)-Cl, dimethyl 1,5-dichloro-9,10-dihydro-9,10-ethenoanthracene-11,12-dicarboxylate, C20H14Cl2O4, P21/n; (1)-CN, 1,5-dicyano derivative, C22H14N2O4, P21/n; (1)-CN.0.5p-xylene, C22H14N2O4.0.5C8H10, P21/c; (1)-CN.xxylene, C22H14N2O4.xC8H10, P21/n; (1)-OMe, 1,5-dimethoxy derivative, C22H20O6, P{\bar 1}; (2b)-Cl, C20H14C12O4, dimethyl 1,5-dichloro-4b,8b,8c,8d-tetrahydrodibenzo[a, f]cyclopropa[c,d]pentalene-8c,8d-dicarboxylate, Pna21. The dibenzobarrelene molecules all have geometries and dimensions similar to those of related materials. In particular, the orientations of the two ester groups in each molecule differ, one being in general almost fully conjugated with the C(11)=C(12) double bond and the other almost non-conjugated. Relationships are sought between the ratios of the two regioisomeric photoproducts and molecular and crystal structures; both electronic and steric effects are considered, but no one effect seems to dominate.

Structures and photochemistry of dibenzobarrelene monoamides

1996 ◽  
Vol 52 (6) ◽  
pp. 1007-1013 ◽  
Author(s):  
R. Jones ◽  
A. G. M. Rattray ◽  
S. J. Rettig ◽  
J. R. Scheffer ◽  
J. Trotter
Keyword(s):  
Crystal Structure ◽  
Double Bond ◽  
Crystal Structures ◽  
Structure Analysis ◽  
Hydrogen Abstraction ◽  
Crystal Structure Analysis ◽  
Amide Group ◽  
Crystal Data

The photochemistry of 9,10-ethenoanthracene-11-monoamides has been studied and correlated with the crystal structures determined for two derivatives; photoproduct structures have been established from a crystal structure analysis of one of the products and from NMR correlations. Crystal data are: (1)-Et, N, N-diethyl-9,10-dihydro-9,10-ethenoanthracene-11-carboxamide, C21H21NO, Pbca; (1)-Pr, 9,10-dihydro-N,N-di(isopropyl)-9,10-ethenoanthracene-11-carboxamide, C23H25NO, P21/c; (2 L)-Bz, 9,10-dihydro-9,10-ethenoanthracene-11-spiro-3′-(1-benzyl-4-phenylazetidine)-2′-one, C31H25NO (+ solvent), P21/a (Z = 8). The two dibenzobarrelene molecules have geometries and dimensions similar to those of related materials; the amide group in each molecule is only partially conjugated with the C 11=C 12 double bond. Mechanisms are derived for the formation of three types of photoproduct: (i) the well known di-π-methane reaction [(2M)-type photoproduct]; (ii) a hydrogen abstraction process (2H); (iii) β-lactam formation (2 L).

scholarly journals E. S. Fedorov Promoting the Russian-German Scientific Interrelationship

Minerals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 181 ◽  
Author(s):  
Peter Paufler ◽  
Stanislav K. Filatov
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Structure Analysis ◽  
Crystalline State ◽  
Crystal Structure Analysis ◽  
Present Knowledge ◽  
Personal Contact ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Impact

At the dawn of crystal structure analysis, the close personal contact between researchers in Russia and Germany, well documented in the “Zeitschrift für Krystallographie und Mineralogie”, contributed significantly to the evolution of our present knowledge of the crystalline state. The impact of the Russian crystallographer E. S. Fedorov upon German scientists such as A. Schoenflies and P. Groth and the effect of these contacts for Fedorov are highlighted hundred years after the death of the latter. A creative exchange of ideas paved the way for the analysis of crystal structures with the aid of X-ray diffraction.

Re: Crystal Structures of Pyroaurite and Sjögrenite

1994 ◽  
Vol 38 ◽  
pp. 749-755 ◽  
Author(s):  
A. Olowe
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Structure Analysis ◽  
Crystal Structure Analysis ◽  
Metallic Ions ◽  
Chemical Formula ◽  
Metal Hydroxides ◽  
Space Group ◽  
Previous Discussion ◽  
Positively Charged

Abstract Pyroaurite and sjogrenite belong to the group of sandwiched lamellar metal hydroxides which have a fixed metallic ions MII:MIII ratio for a particular class. Their crystal structure consists of positively charged metal hydroxide blocks intercalated with negatively charged interlayers. The atomic positions for the interlayer are definite for a particular class. The exact chemical formula of the pyroaurite class is determined from crystal structure analysis to be MII 6MIII 2(OH)16-CO3-4.5H2O; it crystallizes in the space group Rm with a = 12.4376 Å and c = 23.4126 Å. Sjogrenite, MII 6 MIII 2(OH)16-CO3-4H2O crystallizes in the space group P63/mcm. The crystallogiraphy and structural relationship between these classes are discussed. Previous discussion on these compounds did not give any conclusion on the exact chemical formula and the atomic positions.

Zur Reaktion von [MCl2(PR3)2] (M = Ni, Pd) mit E(SiMe3)2 (E = S, Se) Die Kristallstrukturen von [Ni3S2Cl2(PPh3)4], [Pd3S2Cl2(PPh3)4], INi3Se2(SeSiMe3)2(P(C2H4Ph)3)4] und [Pd3Se2(SeSiMe3)2(PPh3)4] / Reaction of [MCl2(PR3)2] (M = Ni, Pd) with E(SiMe3)2 (E = S, Se) The Crystal Structures of [Ni3S2Cl2(PPh3)4], [Pd3S2Cl2(PPh3)4], [Ni3Se2(SeSiMe3)2(P(C2H4Ph)3)4] and [Pd3Se2(SeSiMe3)2(PPh3)4]

1990 ◽  
Vol 45 (2) ◽  
pp. 127-133 ◽  
Author(s):  
Dieter Fenske ◽  
Holm Fleischer ◽  
Harald Krautscheid ◽  
Jörg Magull
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Structure Analysis ◽  
Crystal Structure Analysis ◽  
X Ray ◽  
Triangular Clusters

[MC12(PR3)2] (M = Ni, Pd) reacts with E(SiMe3)2 (E = S, Se) to form triangular clusters, [Ni3S2Cl2(PPh3)4] (1), [Pd3S2Cl2(PPh3)4] (2), [Ni3Se2(SeSiMe3)2(P(C2H4Ph)3)4] (4) and [Pd3Se2(SeSiMe3)2(PPh3)4] (3). 1-4 have been characterized by X-ray crystal structure analysis. All these compounds contain a triangular M3-core, which is capped by two μ3-E-ligands (E = S in 1, Se in 3 and 4).

π-Olefin-Iridium-Komplexe, XVIII [1] Reaktionen von Bis[cycloocta-1,5-dien-μ-chloro-iridium] mit n-Propyllithium in Gegenwart von Alkinen / π-Olefin Iridium Complexes, XVIII [1]Reactions of Bis[cycloocta-l,5-diene-μ-chloro-iridium] with n-Propyllithium in the Presence of Alkynes

1993 ◽  
Vol 48 (11) ◽  
pp. 1558-1564 ◽  
Author(s):  
Jörn Müller ◽  
Ke Qiao ◽  
Regina Schubert ◽  
Matthias Tschampel
Keyword(s):  
Crystal Structure ◽  
Structure Analysis ◽  
Reaction System ◽  
Crystal Structure Analysis ◽  
Steric Effects ◽  
Iridium Complexes ◽  
Substituted Benzenes

The reaction of [(cod)IrCl]2 (cod = η4-cycloocta-1,5-diene) with n-C3H7Li gives non-isola-ble (cod)IrH species by β-elimination of (cod)Ir-n-C3H7 intermediates; the stable final products of further reactions with RC = CR highly depend on the nature of the substituents R. With R = Me the 6-endo-H-hexamethylcyclohexadienyl complex 1 is obtained together with the iridacyclopentadienyl compound 2 and known {[(cod)IrH]4C3H4) (3). In case of R = Et steric effects cause transfer of the hydridic hydrogen to the cod ligand, and the hexaethylbenzene species 4 is isolated which was characterized by crystal structure analysis. The reaction system with tolane again yields a 6-endo-H-cyclohexadienyl complex (5). In all cases free substituted benzenes are formed as cyclotrimerization products of the alkynes.

1-Thiooxamat, NH2C(O)C(S)O , und 2-Thiooxamat, NH2C(S)CO2 als Liganden in Übergangsmetall-Komplexen. Die Strukturen von [Fe(2-thiox)2(H2O)2], [Zn(2-thiox)2(H2O)] und [Zn(1-thiox)2(H2O)]·H2O/ 1-Thiooxamate, NH2C (O)C(S)O– , and 2-Thiooxamate, NH2C(S)CO2–, as Ligands in Transition Metal Complexes. Crystal Structures of [Fe(2-thiox)2(H2O)2], [Zn(2-thiox)2(H2O)] and [Zn(1-thiox)2(H2O)]·H2O

1985 ◽  
Vol 40 (8) ◽  
pp. 1068-1072 ◽  
Author(s):  
Johannes Bertels ◽  
Rainer Mattes
Keyword(s):  
Crystal Structure ◽  
Transition Metal ◽  
Metal Complexes ◽  
Crystal Structures ◽  
Structure Analysis ◽  
Transition Metal Complexes ◽  
Crystal Structure Analysis

AbstractTransition metal complexes of the ligands 1-thiooxamate and 2-thiooxam ate have been prepared. According to crystal structure analysis of Fe(2-thiox)2(H2O)2, Zn(2-thiox)2(H2O) and Zn(1-thiox)2(H2O)2 these ligands act as O .S-donors and form pentaatomic chelaterings. Both Zn-complexes are trigonal-bipyramidally coordinated.

scholarly journals Zur Reaktion von Ni8-Clustern mit Natriumamalgam. Die Kristallstrukturen von {[Ni8Hg(PPh)6(PPh3)4]·[Ni8(PPh)6(PPh3)4]} und [Ni8S6(PPh3)8] / Reaction of Ni8-Clusters with Sodium Amalgam. The Crystal Structures of {[Ni8Hg(PPh)6(PPh3)4] · [Ni8(PPh)6(PPh3)4]} and [Ni8S6(PPh3)8]

1990 ◽  
Vol 45 (2) ◽  
pp. 121-126 ◽  
Author(s):  
Dieter Fenske ◽  
Jörg Magull
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Structure Analysis ◽  
Nickel Atom ◽  
Crystal Structure Analysis ◽  
Mercury Atom ◽  
Symmetrical Structure ◽  
X Ray ◽  
Sodium Amalgam

[Ni8Cl4(μ4-PPh)6(PPh3)4] (1) reacts with sodium amalgam to form [Ni9(PPh)6(PPh3)4] (2) and {[Ni8Hg(PPh)6(PPh3)4] · [Ni8(PPh)6(PPh3)4]} (3). 3 has been characterized by X-ray crystal structure analysis. It contains two distorted cubic Ni8-clusters. All faces of the cubes are occupied by μ4-PPh ligands. At one of the cubes one nickel atom is bonded to an external mercury atom. [Ni8Cl2S6(PPh3)6] (4) reacts with sodium amalgam to form [Ni8S6(PPh3)8] (5). In this symmetrical structure all nickel atoms are bonded to three S ligands and to one PPh3.

Über die Tricyanatomercurate KHg(NCO)3 und RbHg(NCO)3 — Synthesen, Kristallstrukturen und Schwingungsspektren / On the Cyanatomercurates KHg(NCO)3 and RbHg(NCO)3 — Syntheses, Crystal Structures and Vibrational Spectra

1977 ◽  
Vol 32 (11) ◽  
pp. 1239-1243 ◽  
Author(s):  
Gerhard Thiele ◽  
Peter Hilfrich
Keyword(s):  
Crystal Structure ◽  
Aqueous Solutions ◽  
Crystal Structures ◽  
Structure Analysis ◽  
Vibrational Spectra ◽  
Crystal Structure Analysis ◽  
Space Group

By mixing aqueous solutions of Hg(CH3COO)2 and KOCN the white precipitate K2Hg3(NCO)8 is formed. When recrystallised from CH3OH colorless crystals of the compound KHg(NCO)3 are obtained. The crystal structure analysis (space group Pnma; α = 1015.2(6) pm, b = 399.3(3) pm, c = 1772.9(9) pm) shows a distorted KCdCl3 arrangement with isolated Hg(NCO)2 molecules, K+ and NCO- ions. The vibrational spectra in the range of 250-3000 cm-1 are discussed. The rubidium compound is isotypous (a = 1019.0(6) pm, b = 411.6(4) pm, c = 1820.5(8) pm).

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