Dipolar donor-acceptor character

Varian (see Catalog, SPE products) Focus Polar functionalized styrene-divinylbenzene polymer Reversed phase with strong hydrogen bond donor, acceptor, and dipolar character Fluoxetine, verapamil, olanzapine, tramadol, loratidine, and sumatriptane (81) verdanafil (82)... 

For a small molecule with strong donor-acceptor substitution and charge transfer character, the difference dipole moment Ap. is large and the dipolar contribution can be assumed to dominate the two-photon term. 

Such a type of donor-acceptor complex represents an original class of 2D dipolar NLO chromophore, and EFISH and HRS experiments in combination with INDO/singles configuration interaction(SCI)-SOS theoretical calculations have been used to investigate the 2D character of the [3 response in 62 (A = C1) the 2D optical nonlinearity is related to the existence of various low-energy charge transfer states, and while... 

The ability of various molecules to act as H atom donors in photoreduction varies greatly with the Z-H bond energy and with the electron density on the abstractable H atom. Molecules with electron donor groups (amino, hydroxy, etc.) near the H-donor GH group are very efficient. These include some amines, amides, alcohols and ethers hydrocarbons are substantially poorer H-donors and pure aromatics like benzene show very little reactivity. Acetonitrile H3C-CN is a very poor H-atom donor because its C-H bonds are made dipolar by the action of the strong electron acceptor CN so that the electron density on H is low. Water itself is an extremely bad H-atom donor in view of both the high OH bond energy and the acidic character of these bonds. 

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