An investigation of the interaction of 4-membered rings with adjacent carbanion centers

Guven, OO
Peynircioğlu, Nihad Bekir
A series of cyclobutylcarbinyl phenyl ketones was prepared and the rates of base catalyzed hydrogen-deuterium exchange of a-hydrogen atoms were compared with those of appropriate model compounds, to test the validity of an earlier finding, which suggested that a four-membered ring, like the three-membered ring, has the ability to stabilize an adjacent carbanion center. In this study, unlike the cyclopropyl group, no clearly defined stabilization of the adjacent, carbanion center was detected by the 1-phenyl- and 1-p-nitrophenyl- substituted cyclobutyl groups and only a very slight rate enhancement by the 3-phenylcyclobutyl group was detected. Attempts to detect a stabilization of the carbanion center by a cyclobutyl-substituted methyl group (homoconjugative interaction) also failed.


The effect of boron substitution on cyclacenes
Türker, Burhan Lemi; Azizoglu, A (2001-01-15)
AM1-type semiempirical molecular orbital treatment was performed on the Huckel-type cyclacenes having certain number of boron atoms at the peri-positions and at the fusion sites of the arenoid rings. The effect of boron atoms is generally destabilizing in all the cases as compared to their unsubstituted cyclacene counterparts. The AM1 results revealed that certain properties of the boron-substituted cyclacenes are affected not only by the number of arenoid rings they have but also by the nature of their per...
A Density Functional Theory Study of Direct Oxidation of Benzene to Phenol by N2O on a [FeO](1+)-ZSM-5 Cluster
Fellah, Mehmet Ferdi; Önal, Işık; van Santen, Rutger A. (2010-07-29)
Density functional theory calculations were carried out in a study of the oxidation of benzene to phenol by N2O on a model (FeO)(1+)-ZSM-5 cluster: the [(SiH3)(4)AlO4(FeO)] cluster. This cluster models the reactivity of Fe3+ oxidic clusters. Results are to be compared with an earlier study (J. Phys. Chem. C 2009, 113, 15307) on a model Fe2+-ZSM-5 cluster. The true activation energies for the elementary reaction step in which phenol is produced appear to be comparable. The major difference between the two sy...
Karakaş, Gürkan (Wiley, 1989-01-01)
Effects of concentration changes in initiator species Na2SO3, (NH4)2S2O8 and CuSO4, and emulsifier, ammonium stearate, on poly(vinyl chloride) (PVC) emulsion polymerization kinetics and on product particle size were experimentally investigated. It was observed that to obtain industrially significant rates and overall conversions, not only an optimum concentration ratio of Na2SO3/(NH4)2S2O8/CuSO 4 must be used, but also the concentrations of these species must be above certain limits. Increasing the concentr...
A density functional theory study of oxidation of benzene to phenol by N2O on Fe- and Co-ZSM-5 clusters
Fellah, Mehmet Ferdi; Önal, Işık (2009-06-01)
Density functional theory (DFT) calculations were carried out in the study of oxidation of benzene to phenol by N2O on relaxed [(SiH3)(4)AlO4M] (where M=Fe, Co) cluster models representing Fe- and Co-ZSM-5 surfaces. The catalytic cycle steps are completed for both Fe-ZSM-5 and Co-ZSM-5 clusters. The general trend of the results that were obtained in terms of activation barriers for the Fe-ZSM-5 cluster is in agreement with the experimental and theoretical literature. It was observed that the phenol formatio...
A van der Waals density functional investigation of carboranethiol self-assembled monolayers on Au(111)
Yılmaz, Ayşen; Danışman, Mehmet Fatih (2016-05-14)
Isolated and full monolayer adsorption of various carboranethiol (C2B10H12S) isomers on the gold(111) surface has been investigated using both the standard and van der Waals density functional theory calculations. The effect of different molecular dipole moment orientations on the low energy adlayer geometries, the binding characteristics and the electronic properties of the self-assembled monolayers of these isomers has been studied. Specifically, the binding energy and work function changes associated wit...
Citation Formats
O. Guven and N. B. Peynircioğlu, “An investigation of the interaction of 4-membered rings with adjacent carbanion centers,” TURKISH JOURNAL OF CHEMISTRY, pp. 153–158, 2002, Accessed: 00, 2020. [Online]. Available: