Chlorine substitution, effect

Investigation of Chlorine Substitution Effects in the Claisen-Schmidt Condensation of 2 -Hydroxyacetophenone with Chlorobenzaldehydes Over MgO... 

Furukawa K, N Tomizuka, A Kamibayashi (1979) Effect of chlorine substitution on the bacterial metabolism of various polychlorinated biphenyls. Appl Environ Microbiol 38 301-310. 

At the second stage of chlorine substitution in the tetramers there is a greater statistical probability for the incoming nucleophile to attack the phosphorus adjacent to =P(C1)(NHR), viz. P4 or P8, rather than the remote phosphorus, viz. P6 (Fig. 9). However, this statistical effect is countered by the electron releasing effect of the substituent already present on P2, which tends to deactivate P2 as well as P4 and P8 towards further nucleophilic substitution. It is observed that reactive amines such as dimethylamine (94) or ethylamine (95) react with N4P4C18 and... 

Gamer, C. and Matthews, H. (1998). The effect of chlorine substitution on the dermal absorption of polychlorinated biphenyls. Toxicol. Appl. Pharmacol. 149 150-158. 

Figure 19. Position of two bromine atoms in the phenyl ring shows similarities in its effect on blood pressure to chlorine substituted phenyl-imino—imidazolines...

Sampling rates at different temperatures have been determined by Huckins et al. (1999) for PAHs at 10,18, and 26 °C, by Rantalainen et al. (2000) for PCDDs, PCDFs, and non-ortho chlorine substituted PCBs at 11 and 19 °C, and by Booij et al. (2003a) for chlorobenzenes, PCBs, and PAHs at 2,13 and 30 °C. The effect of temperature on the sampling rates can be quantified in terms of activation energies (A a) for mass transfer, as modeled by the Arrhenius equation... 

In the case of mono-olefins halogen substituents again reduce the basicity, as in the case of benzene. Unfortunately no information is available which would permit a comment as to whether the halogen atom causes this effect only if it is directly linked to the C=C double bond or whether an effect is also still exerted by an adjacent saturated halogen-substituted C-atom. With multiple halogen substitution the basicity falls even more as may be seen from the examples of chlorine-substituted ethylenes in Table 17. 

Introduction of more than one methyl group into the aromatic ring giving 5,7-, 6,7-, or 5,8-disubstituted compounds, resulted in loss of all activity [94, 138]. The effect of chlorine substitution follows a rather similar pattern [138]. The adrenergic neurone blocking activity of guanoxan is maintained in the homologous compound in which the side chain is increased by one carbon... 

In contrast, methyl-for-chlorine substitution is decidedly nonlinear, a feature also displayed by the lighter Group 14 compounds. This curvature is not an artifact of the BAC-MP4 predictions, since it is observable in the (admittedly limited) experimental data for these compounds (Fig. 10). In fact, the deviations from linearity are even greater in the experimental data. Such behavior is also observed in the analogous Si compounds and is related to the negative hypercongugation (anomeric) effect, in which electron density from... 

These different synthetic approaches result in structurally different materials and it is important to quantify these effects in terms of lithographic performance so that an optimum synthetic procedure might be identified. In particular, it is important to quantify lithographic performance as a function of the position of chlorine substitution on the polymer molecule. 

In anhydrous hydrogen fluoride medium, chlorine monofluoride effects the substitution of chlorine by fluorine in organo-chlorine compounds at - 60 to 10 C on bubbling into emulsions of the latter.107... 

Furukawa, K., Tonomura, K. Kamibayashi, A. (1978a). Effect of chlorine substitution on the biodegradability of polychlorinated biphenyls. Applied and Environmental Microbiology, 35, 223-7. 

The effect of chlorine substitution is to reduce the C-O bond energy of the peroxy radicals from 32kcal/mol for CH302 to 20kcal/mol for CC1302. 

Rghei HO, Eiceman GA. 1985. Effect of matrix on heterogeneous phase chlorine substitution reactions for dibenzo-p-dioxin and hydrochloric-acid in air. Chemosphere 14 167-172. 

UV-visible spectral measurements show that substituted indolo[ 3,2-ib] carbazoles (5) absorb significantly below 450 nm (Fig. 4.12). Their band gaps in the solid state, estimated from the on-set UV-visible absorption, were >2.55 eV, which are significantly larger than those of most p-channel organic semiconductors for OTFTs (Table 4.1). In addition, whereas chlorine substitution at the 3,9 positions of 5,ll-dialkylindolo[3,2-jb]carbazole (i.e. 5d) did not cause noticeable changes in the spectral properties, substitution at the 2,8 positions (i.e. 5c) results in red-shifts in both solution and thin film absorption - a phenomenon that clearly indicates the pronounced electronic effects of substituents at positions para to the radical cation sites (5-N and 11-N positions). 

This is one of the rare cases where a non-containing Ge ion is the base peak. The effect of multiple chlorine substitution on the mass spectra of the phenyl derivatives46 is shown in Table 5. 

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