Relations between 77Se NMR chemical shifts of (phenylseleno)benzenes and their molecular structures derived from nine X-ray crystal structures

2003 ◽  
Vol 1 (6) ◽  
pp. 1053-1060 ◽  
Author(s):  
Jette Oddershede ◽  
Lars Henriksen ◽  
Sine Larsen
Keyword(s):  
Crystal Structures ◽  
Chemical Shifts ◽  
Molecular Structures ◽  
X Ray ◽  
Nmr Chemical Shifts

Assigning structures to diastereomeric aliphatic α,α'-dibromo ketones

2002 ◽  
Vol 80 (4) ◽  
pp. 413-417 ◽  
Author(s):  
Masood Parvez ◽  
SM Humayan Kabir ◽  
Ted S Sorensen ◽  
Fang Sun ◽  
Brian Watson
Keyword(s):  
Liquid Chromatography ◽  
Key Words ◽  
Crystal Structures ◽  
Chemical Shifts ◽  
Gas Liquid Chromatography ◽  
X Ray ◽  
Nmr Chemical Shifts ◽  
H Nmr ◽  
Dibromo Ketones

X-ray crystal structures are reported for two symmetrical aliphatic α,α'-dibromo ketones: a meso diastereomer of 3,5-dibromo–2,2,6,6-tetramethylheptan-4-one, and a rac isomer of 4,6-dibromo–2,2,3,3,7,7,8,8-octamethylnonan-5-one. Using these secure assignments and a previously confirmed structure for the diastereomers of 2,4-dibromopentan-3-one, we show in this study that gas-liquid chromatography (GLC) retention times (meso > rac) can be used to confidently assign the diastereomers for a range of symmetrical and unsymmetrical aliphatic α,α'-dibromo ketones. 1H NMR chemical shifts for the >CHBr hydrogen(s) can also be corroboratively used for assignment purposes (δracH > δmesoH).Key words: α,α'-dibromo ketones, X-ray crystal structures, GLC retention times, isomer assignment

Synthesis, X-ray structure determination, and formation of 3,4,5-trichloroguaiacol occurring in kraft pulp spent bleach liquors

1980 ◽  
Vol 58 (8) ◽  
pp. 815-822 ◽  
Author(s):  
K. Lindström ◽  
F. Österberg
Keyword(s):  
Reaction Mechanism ◽  
Melting Point ◽  
Structure Determination ◽  
Kraft Pulp ◽  
Chemical Shifts ◽  
X Ray ◽  
Nmr Chemical Shifts ◽  
Chemical Pulp ◽  
C Nmr

3,4,5-Trichloroguaiacol, which is formed during bleaching of chemical pulp and shown to bioaccumulate in fish, has been synthesized. The structure of the compound has been determined by means of X-ray analysis. The values of the 13C nmr chemical shifts and melting point differ from those previously reported. A reaction mechanism is suggested for the formation of 3,4,5- and 4,5,6-trichloroguaiacol.

Lewis-Base Adducts of Group 1B Metal(I) Compounds. XXI The Crystal and Molecular Structures of the Unsolvated Forms of Dibromotris(triphenylphosphine)dicopper(I) and 'step' Tetrabromotetrakis(triphenyl-phosphine)tetracopper(I)

1985 ◽  
Vol 38 (8) ◽  
pp. 1243 ◽  
Author(s):  
JC Dyason ◽  
LM Engelhardt ◽  
C Pakawatchai ◽  
PC Healy ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Molecular Structures ◽  
Lewis Base ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Triphenyl Phosphine ◽  
X Ray ◽  
Crystal And Molecular Structures

The crystal structures of the title compounds have been determined by single-crystal X-ray diffraction methods at 295 K. Crystal data for (PPh3)2CuBr2Cu(PPh3) (1) show that the crystals are iso-morphous with the previously studied chloro analogue, being monoclinic, P21/c, a 19.390(8), b 9.912(5), c 26.979(9) Ǻ, β 112,33(3)°; R 0.043 for No 3444. Cu( trigonal )- P;Br respectively are 2.191(3); 2.409(2), 2.364(2) Ǻ. Cu(tetrahedral)- P;Br respectively are 2.241(3), 2.249(3); 2.550(2), 2.571(2) Ǻ. Crystals of 'step' [PPh3CuBr]4 (2) are isomorphous with the solvated bromo and unsolvated iodo analogues, being monoclinic, C2/c, a 25.687(10), b 16.084(7), c 17.815(9) Ǻ, β 110.92(3)°; R 0.072 for No 3055. Cu( trigonal )- P;Br respectively are 2.206(5); 2.371(3), 2.427(2) Ǻ. Cu(tetrahedral)- P;Br are 2.207(4); 2.446(2), 2.676(3), 2.515(3) Ǻ.

THE RELATION OF 15N NMR, 1H NMR CHEMICAL SHIFTS WITH THE ATOMIC NET CHARGE AND MOLECULAR STRUCTURES

1987 ◽  
Vol 3 (06) ◽  
pp. 632-637
Author(s):  
Chen Yuehua ◽  
◽  
Guo Guolin ◽  
Shen Qifeng ◽  
Zhao Yufen ◽  
...  
Keyword(s):  
Chemical Shifts ◽  
Molecular Structures ◽  
Net Charge ◽  
Nmr Chemical Shifts ◽  
H Nmr

Spirocyclic tin salicyl alcoholates – a combined experimental and theoretical study on their structures, 119Sn NMR chemical shifts and reactivity in thermally induced twin polymerization

2019 ◽  
Vol 48 (1) ◽  
pp. 220-230
Author(s):  
Philipp Kitschke ◽  
Ana-Maria Preda ◽  
Alexander A. Auer ◽  
Sebastian Scholz ◽  
Tobias Rüffer ◽  
...  
Keyword(s):  
Theoretical Study ◽  
Chemical Shifts ◽  
Molecular Structures ◽  
Thermally Induced ◽  
Nmr Chemical Shifts ◽  
119Sn Nmr

Studies on a series of spirocyclic tin salicyl alcoholates regarding their molecular structures and their reactivity in twin polymerization are presented.

Solution and Solid-State Effects on NMR Chemical Shifts in Sesquiterpene Lactones: NMR, X-ray, and Theoretical Methods

2011 ◽  
Vol 116 (1) ◽  
pp. 680-688 ◽  
Author(s):  
Martin Dračínský ◽  
Miloš Buděšínský ◽  
Beata Warżajtis ◽  
Urszula Rychlewska
Keyword(s):  
Solid State ◽  
Chemical Shifts ◽  
Sesquiterpene Lactones ◽  
Theoretical Methods ◽  
X Ray ◽  
Nmr Chemical Shifts

Syntheses, Crystal Structures and Electrochemical Properties of Acetylacetonato-Ruthenium Complexes Containing Substituted Pyridine Ligands

2013 ◽  
Vol 68 (9) ◽  
pp. 993-999 ◽  
Author(s):  
Xiuli Wu ◽  
Rufei Ye ◽  
Ai-Quan Jia ◽  
Qun Chen ◽  
Qian-Feng Zhang
Keyword(s):  
Electrochemical Properties ◽  
Crystal Structures ◽  
Zinc Dust ◽  
Ruthenium Complexes ◽  
Reducing Agent ◽  
Molecular Structures ◽  
X Ray ◽  
X Ray Crystallography ◽  
Crystal And Molecular Structures ◽  
Pyridine Ligands

Treatment of Ru(acac)3 with 2-cyano-pyridine and 3,5-dimethyl-pyridine in the presence of zinc dust as reducing agent in refluxing THF afforded the ruthenium(II) complexes cis-[RuII(acac)2(2- CN-py)2] (1) and cis-[RuII(acac)2(3,5-Me2-py)2] (2), respectively. Interaction of Ru(acac)3 with 3- Me-pyridine and 3,5-Me2-pyridine in the presence of Br2 in refluxing THF gave the ruthenium(III) complexes [RuIII(acac)Br2(3-Me-py)2] (3) and [RuIII(acac)Br2(3,5-Me2-py)2] (4), respectively. The four complexes have been spectroscopically and electrochemically characterized, and their crystal and molecular structures have been established by X-ray crystallography

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