Browse Prior Art Database

2 Substituted Nitropyridines as Nonlinear Optical Materials

IP.com Disclosure Number: IPCOM000051176D
Original Publication Date: 1982-Aug-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Cheng, YY: AUTHOR [+4]

Abstract

A number of 2 x 5 nitropyridines (Table I) and 2 x 3,5-dinitropyridines (Table II) have properties which render them useful as frequency doublers. Herein, x is a substituent in which the atom of attachment to the pyridine ring has available electron pair(s) which make x an electron donor, typical atoms being O,S,N, halogen, etc. Most of the compounds described in Tables I and II have been prepared by nucleophilic aromatic substitution of the chlorine in commercially available 2 chloro 5 nitropyridine 1 or 2 chloro 3,5-dinitropyridine 9. Not all members of this class of pyridines are active doublers in the crystalline state since a noncentrosymmetric unit cell is required for second harmonic generation.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 72% of the total text.

Page 1 of 2

2 Substituted Nitropyridines as Nonlinear Optical Materials

A number of 2 x 5 nitropyridines (Table I) and 2 x 3,5-dinitropyridines (Table
II) have properties which render them useful as frequency doublers. Herein, x is a substituent in which the atom of attachment to the pyridine ring has available electron pair(s) which make x an electron donor, typical atoms being O,S,N, halogen, etc. Most of the compounds described in Tables I and II have been prepared by nucleophilic aromatic substitution of the chlorine in commercially available 2 chloro 5 nitropyridine 1 or 2 chloro 3,5-dinitropyridine 9. Not all members of this class of pyridines are active doublers in the crystalline state since a noncentrosymmetric unit cell is required for second harmonic generation. The incidence of activity is dramatically increased when the x substituent is derived from a pure (or at least highly enriched) enantiomer necessarily producing an enantiomorphous crystal system as in compounds 6 and 12. More rarely a racemic substance will crystallize in a noncenfrosymmetric fashion, and these derivatives will also be active doublers.

A wide variety of these pyridine derivatives have been prepared; a nonexhaustive compilation of representative materials is given in Tables I and II which provides typical structural and doubling properties. These pyridine derivatives have UV cutoffs in the region of 400-450 nm, making them potentially useful for doubling semiconductor laser radiation and ma...