Microphase Coatings, Inc, 170 Donmoor Court, Garner, NC 27529, USA Table 1: Summary of model predictions for the reaction of TIP with TPG, glycerol, and water Case 1 Case 2 Case 3 Case 4 Number of possible reaction 56 28 10 3 paths Number of reaction paths which 5 (9%) 6 (21%) 2 (20%) 3 (100%) produce intermediate compounds having 3 TPG substituents
Number of different products 10 7 5 3 formed Number of products with 0 TPG 4 3 0 1 substituents
Number of products with 1 TPG 4 4 3 0 substituent
Number of products with 2 TPG 2 0 2 2 substituents
Besides the additional hydrophobation of the silica surface, the long-chain substituents
generate a certain steric hindrance for the mercapto group.
The possibility of distinguishing of the reaction centre from the remaining part of the corresponding molecule (for instance, the substituent
) is introduced.
The 25 units of the input layer contain chemical information about the first-ring substituent
. Through synapse-like connections that can either strengthen or weakne, these units funnel into, and collectively either excite or inhibit, each of the middle layer's five members.
As it can be seen from Table 1, the activation barriers of reactions of olefins with electron-donating substituents
are lower compared to the parent (unsubstituted) ethylene except for propene.
Under the present reaction conditions, because of the different substituents
on the orthoesters, the reaction time and yield resulting in a slight difference, but both aliphatic and aromatic groups of orthoesters can result in moderate to good yields of the desired product.
The chemical shift [delta]CH=N (ppm) values of all the (E)-1-benzylidene-2-(3-nitrophenyl)hydrazine compounds have been correlated with Hammett substituents
constants and F and R parameters using single-linear and multi-linear regression analysis [34-39].
Conclusions: Electron-withdrawing substituents
reduced the shift towards the products of the secondary and tertiary Leuckart reactions.
Therefore, the incorporation of these side groups into polyphosphazenes as single substituents
or cosubstituents could generate interesting properties.
of 2-substituted phenylhydrazones having substituents
other than a methoxy group
Several methods such as incorporation of porous material into the polymer matrix [3-9], thermal degradation of labile graft or block chains in the polyimides [10, 11], introduction of bulk fluorinated substituents
into the polymer backbone [9, 12-16], and so forth, were applied to reduce dielectric constant.