Dalton perspectives. Bond stretch isomerism: fact or artifact?

1992 ◽  
pp. 947 ◽  
Author(s):  
Vernon C. Gibson ◽  
Mary McPartlin
Keyword(s):  
Bond Stretch

Far Infrared Group Frequencies. V. Oximes and Aldoximes

1973 ◽  
Vol 27 (1) ◽  
pp. 22-26 ◽  
Author(s):  
S. M. Craven ◽  
F. F. Bentley ◽  
D. F. Pensenstadler
Keyword(s):  
Hydrogen Bond ◽  
Infrared Spectra ◽  
Low Frequency ◽  
Far Infrared ◽  
Torsional Vibrations ◽  
Lattice Vibrations ◽  
Dilute Solutions ◽  
Solid Samples ◽  
Bending Modes ◽  
Bond Stretch

The low frequency infrared spectra from 450 to 75 cm−1 of seven oximes and five aldoximes have been recorded for pure samples and for dilute solutions in cyclohexane. An intense characteristic band is present in the solution spectra at 367 ± 10 cm−1. This characteristic band shifts to 275 ± 10 cm−1 in the spectra of the OD compounds. The 367 ± 10 cm−1 and 275 ± 10 cm−1 bands are assigned to OH and OD torsional vibrations. A comparison of the solution spectra with spectra of the solid samples indicated that the OH … N hydrogen bond stretch of oximes and aldoximes occurs in 300 to 200 cm−1 region. Strong bands also are present in 140 to 100 cm−1 region which are due to OH … N bending modes or perhaps lattice vibrations.

Tuning the Metal−Metal Bonds in the Linear Tricobalt Compound Co3(dpa)4Cl2:  Bond-Stretch and Spin-State Isomers

2001 ◽  
Vol 40 (6) ◽  
pp. 1256-1264 ◽  
Author(s):  
Rodolphe Clérac ◽  
F. Albert Cotton ◽  
Lee M. Daniels ◽  
Kim R. Dunbar ◽  
Carlos A. Murillo ◽  
...  
Keyword(s):  
Spin State ◽  
Metal Metal ◽  
Metal Metal Bonds ◽  
Metal Bonds ◽  
Bond Stretch

Bond-stretch Isomerism in Polyoxometalates?

2006 ◽  
pp. 117-133
Author(s):  
M. -M. Rohmer ◽  
M. Benard ◽  
E. Cadot ◽  
F. Secheresse
Keyword(s):  
Bond Stretch

scholarly journals Negative Poisson's ratio in 2D life-boat structured crystals

2019 ◽  
Vol 1 (3) ◽  
pp. 1117-1123 ◽  
Author(s):  
Ruhao Fang ◽  
Xiangyuan Cui ◽  
Catherine Stampfl ◽  
Simon P. Ringer ◽  
Rongkun Zheng
Keyword(s):  
Poisson’S Ratio ◽  
Poisson's Ratio ◽  
Strongly Correlated ◽  
Negative Poisson’S Ratio ◽  
Negative Poisson's Ratio ◽  
Bond Stretch

The auxetic behavior is strongly correlated to the bond stretch or rotation and a method to discover it is provided.

Is bond stretch isomerism in mononuclear transition metal complexes a real issue? The misleading case of the MoCl5/tetrahydropyran reaction system

2015 ◽  
Vol 44 (28) ◽  
pp. 12653-12659 ◽  
Author(s):  
Francesco Paolo Di Nicola ◽  
Massimiliano Lanzi ◽  
Fabio Marchetti ◽  
Guido Pampaloni ◽  
Stefano Zacchini
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Reaction System ◽  
Real Issue ◽  
System P ◽  
Bond Stretch

The MoCl5/tetrahydropyran reaction system provides an opportunity for discussing the possible generation of bond stretch isomers.

Theoretical studies of bond stretch isomerism in silabicyclobutanes

1989 ◽  
Vol 93 (8) ◽  
pp. 2888-2891 ◽  
Author(s):  
Jerry A. Boatz ◽  
Mark S. Gordon
Keyword(s):  
Theoretical Studies ◽  
Bond Stretch

Pyrazinyl- and pyrimidinylketenes, bisketenes, and ylides: direct observation and nucleophilic reactivity

2014 ◽  
Vol 92 (12) ◽  
pp. 1119-1130 ◽  
Author(s):  
Annette D. Allen ◽  
Andrei V. Fedorov ◽  
Nanyan Fu ◽  
Shinjiro Kobayashi ◽  
Thomas T. Tidwell ◽  
...  
Keyword(s):  
Aromatic Ring ◽  
Direct Observation ◽  
Uv Absorption ◽  
Ir Absorption ◽  
Aromatic System ◽  
Nucleophilic Reactivity ◽  
Transient Intermediates ◽  
Isomeric Structures ◽  
Bond Stretch

Pyrazinylketene (9) and 4-pyrimidinylketene (11), identified by their IR absorption at 2128 and 2130 cm−1, respectively, are formed in CH3CN as transient intermediates by photolysis of the corresponding diazoketones. The corresponding ylides 10 and 12 are formed concurrently as longer-lived intermediates identified by their distinctive IR and UV absorption. Reactions of 2-pyridylketene and of 9 and 11 with diethylamine form initial amide enol intermediates leading to dihydroheteroarene intermediates and then to amides, whereas amide enols are not observed in reactions with n-butylamine. Reactions with water give observable dihydroheteroarenes. 2,5-Bis(ketenyl)pyrazine (33) is formed by photolysis of 2,5-bis(diazoacetyl)pyrazine (32) together with the corresponding bis(ylide) 35. The latter is calculated to have two geometrically isomeric structures (bond-stretch isomers) with similar energies, one with a central six-membered aromatic ring and another with a 10-pi electron aromatic system.

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