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'Isomer' in keywords

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1	Author	J. Heldt, J. R. Heldt, T. Redzimski, H. Diehl, P. Schultz	Requires cookie*
	Title	Spectroscopic Studies of Dimethylamino Derivatives of Fluorene
	Abstract	2-dimethylamino-9-fluorenol and 2-dimethylamino-9(4'dimethylamino)phenyl-9-fiuorenol in polar solvents in the excited state undergo conformation changes in which two fluorescent isomers are created. The isomers (in the local excited (LE) and charge transfer (CT) configuration) pos-sess separate fluorescence bands, one appearing from the S! (LE) state and the second from the intramolecular charge transfer state S, (CT) of the neutral, aromatic molecule. Both bands show a solvatochromic effect. Using the method of the solvent induced Stokes shift of the absorption and fluorescence spectra the permanent dipole moment of the excited state of fluorene and its two derivatives have been determined. The dipole moment of the ground state and the Onsager cavity radius of the studied molecules were calculated with the Auestion Model 1 (AMI) program.
	Reference	Z. Naturforsch. 55a, 902—908 (2000); received October 31 2000
	Published	2000
	Keywords	Isomer, Dual Fluoescence, Solvatochromic Effect, Charge Transfer
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	TEI-XML for	default:Reihe_A/55/ZNA-2000-55a-0902.pdf
	Identifier	ZNA-2000-55a-0902
	Volume	55

2	Author	Joachim Fuchs, Axel Thiele, Rosemarie Palm	Requires cookie*
	Title	Strukturen und Schwingungsspektren des Tetramethylammonium -a -dodekawolframatosilikats und des Tetrabutylammonium-/?-dodekawolframatosilikats Structures and Vibrational Spectra of Tetramethylammonium a-Dodecatungstosilicate and Tetrabutylammonium /?-Dodecatungstosilicate
	Abstract	Dodecatungstosilicates free of crystal water were prepared for the first time by using tetraalkylammonium as cation. The crystal structure of the tetramethylammonium a-dodeeatungstosilicate [N(CH3)4]4SiWi2C>4o (1) and tetrabutylammonium)S-dodecatungs-tosilicate, [N(C4H9)4]4SiWi204o (2) were solved by X-ray diffraction. (1) crystallizes tetragonal in the space group 14 with lattice parameters a = 14.642 A; c= 12.706 A; (2) orthorhombic, space group P2i2x2i with a = 29.277 A, b = 22.181 A and c = 15.381 A. The differences between the two isomeric heteropolyanions are discussed, especially the distances and angles between the tungsten atoms. Comparison of characteristic differences in the vibrational spectra permits the identifica-tion of the isomeric anions.
	Reference	Z. Naturforsch. 36b, 161—171 (1981); eingegangen am 22. Oktober 1980
	Published	1981
	Keywords	Dodecatungstosilicates, Isomers, X-ray, Vibrational Spectra
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	TEI-XML for	default:Reihe_B/36/ZNB-1981-36b-0161.pdf
	Identifier	ZNB-1981-36b-0161
	Volume	36

3	Author	Günter Schmid, Roland Boese	Requires cookie*
	Title	Azaborolinyl Complexes, IX [1] The Crystal and Molecular Structures of Two Isomers of Bis(l-ter£-butyl-2-methyl-??-l,2-azaborolinyl)cobalt
	Abstract	The crystal and molecular structures of two isomers of bis(l-£er£-butyl-2-methyl-??-l,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 tferi-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.
	Reference	Z. Naturforsch. 38b, 485—492 (1983); eingegangen am 12. November 1982
	Published	1983
	Keywords	Azaborolinyl Sandwich Complexes, Cobalt, Isomers, X-Ray
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	TEI-XML for	default:Reihe_B/38/ZNB-1983-38b-0485.pdf
	Identifier	ZNB-1983-38b-0485
	Volume	38

4	Author	Uwe Klingebiel, Norbert Vater, William Clegg, Martin Haase, GeorgeM. Sheldrick	Requires cookie*
	Title	Synthesis of Silicon-Phosphorus-Rings - Structure of a cis-2,2,4,4-Tetrakis(silylamino)-l,3-diphospha-2,4-disilacyclobutane
	Abstract	Fluorosilylphosphanes of the type R2SiFPHR' (R = CHMe2, CMe3, NMeSiMe3; R' = H, C6H5; 1-4) are obtained in the reaction of difluorosilanes with lithiated phosphanes in a molar ratio 1:1. Diphosphasilanes (5, 6) and a difluorosilylphosphane (7) are isolated as by-products. 1-4 react with w-QjHgLi to give cyclic silylphosphanes, LiF, and C4H10 (8-11). Dilithiated 5 reacts with F2PN(CMe3)SiMe3 to form of a four-membered SiP3-ring 12. The 31 P NMR spectra of 9 and 11 show signal coalescence for the eis-and tfrans-isomers at room temperature. The crystal structure of the cis-isomer of 11 has been determined. The substituted ring 13 is prepared in the reaction of lithiated 9 and Me2SiF2.
	Reference	Z. Naturforsch. 38b, 1557—1562 (1983); eingegangen am 6. Juli 1983
	Published	1983
	Keywords	Fluorosilylphosphanes, Cyclisation, P-Inversion, Isomers, Crystal Structure
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	TEI-XML for	default:Reihe_B/38/ZNB-1983-38b-1557.pdf
	Identifier	ZNB-1983-38b-1557
	Volume	38

5	Author	JanA K Du Plessis, Hans Rose, RobertA. Shaw	Requires cookie*
	Title
	Abstract	The synthesis of trimethylphosphazenyl -and triphenylphosphazenyl -fluorocy clotri -phosphazatrienes, N3P3F6-n(NPR3)n, by a silylation method using Me3SiNPR3 (R = Me or Ph) is reported. More phosphazenyl groups can be introduced if R = Me than if R = Ph. Isomers have been isolated, as have been mixed phosphazenyl derivatives, N3P3F6 -n-m (NPR3)N(NPR3') m (R = Ph, R' = Me). Substituted fluorophosphazenes,
	Reference	(Z. Naturforsch. 31b, 997—998 [1976]; received March 4/April 2 1976)
	Published	1976
	Keywords	Trimethylphosphazenylfluorocyclotri-phosphazatrienes, Triphenylphosphazenylfluorocyclotri-phosphazatrienes, Isomers, Silylation Method, Steric Effects
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	TEI-XML for	default:Reihe_B/31/ZNB-1976-31b-0997_n.pdf
	Identifier	ZNB-1976-31b-0997_n
	Volume	31

6	Author	Joachim Fuchs	Requires cookie*
	Title	Kristallstrukturen und Schwingungsspektren zweier
	Abstract	isomerer Oktadekawolframatodiarsenate, (NH4)6As2W180 62 • #iH20 C rystal S tructures and V ibrational Spectra of Tw o Isom ers of O ctadecatungsto-diarsenate (N H 4)6A s2W 18 0 6 2 • mH20 H o lg er N eu b e rt Six possible structures of A s2W ,80 626~ are discussed, and an exact nom enclature is proposed. The structures of the isomeric title compounds (I and II) were determ ined by X-ray diffraction. I crystallizes in space group P I with lattice param eters a = 12.965(4), b = 14.803(5), c = 18.515(6) Ä; a = 96.280(23)°, ß = 91.420(25)°, y — 115.320(25)°. The anion has the configuration first observed in K6P2W ,80 62-14 H 20 (D awson-structure). II was not known until now. It crystal lizes in the trigonal space group R 3 with lattice param eters a — b — 37.857(32). c = 13.108(13) Ä; a — ß = 90°, y = 120°. The structure of this anion differs from the D awson-structure by the 60° rotation of both polar groups of three W 0 6-octahedra (/3-type), followed by the 60° rotation of one of the two new AsWyO,,-units. Both rotations are about the 3-fold axis. The anion is centrosym m etric. Vibrational spectra and preparation of the isomers are described.
	Reference	Z. Naturforsch. 42b, 951—958 (1987); eingegangen am 4. März/11. Mai 1987
	Published	1987
	Keywords	T ungstoarsenates, Isomers, X-Ray, V ibrational Spectra, Preparation
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	TEI-XML for	default:Reihe_B/42/ZNB-1987-42b-0951.pdf
	Identifier	ZNB-1987-42b-0951
	Volume	42