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Liquid scintillators. XIII. steric inhibition of resonance in liquid scintillators
Author(s) -
Taber Richard L.,
Daub Guido H.,
Hayes F. Newton,
Ott Donald G.
Publication year - 1965
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570020214
Subject(s) - chemistry , toluene , cycloheptene , fluorene , azepine , medicinal chemistry , steric effects , nuclear chemistry , stereochemistry , organic chemistry , polymer
2″,3′ ‐ Dimethyl ‐ p ‐ quaterphenyl (I), 2″, 3′, 5′, 6″ ‐tetramethyl ‐ p ‐ quaterphenyl (II), 6,7 ‐ dihydro ‐ 6 ‐ methyl ‐ 3, 9 ‐ diphenyl ‐ 5 H ‐ dibenz[c,e]azepine (III), 5,7 ‐ dihydro ‐ 3, 9 ‐ diphenyl ‐ dibenzo[c,e]thiepin (IV), 5,7 ‐ dihydro ‐ 3,9 ‐ diphenyldibenzo[c,e]selenepin (V), and 6, 6 ‐ dicarbethoxy ‐ 6,7 ‐ dihydro ‐ 3,9 ‐ diphenyl ‐ 5 H ‐ dibenzo[a,c]cycloheptene (VI) have been synthesized and screened as potential primary liquid scintillation solutes. The scintil‐ lation properties of I, II, III, IV, V, and VI have been compared with 2,7‐diphenyl‐ fluorene (VII) (4), 9,10‐dihydro‐2,7‐diphenylphenanthrene (VIII) (5), and 5,7‐dihydro‐ 3, 9‐diphenyldibenz[c,e]oxepin (IX) (5). The relative pulse‐heights of I, VI, VII, VIII, and IX at 3 mM in toluene gave a linear relationship when plotted against the cos 2 of the respective estimated angles of torsion about the 1″. 4′‐bond in the p ‐quaterphenyl system. The azepine III, thiepin IV, selenepin V, and tetramethyl‐ p ‐quaterphenyl II were very poor scintillators in toluene solution.