Role of free space and conformational control on photoproduct selectivity of optically pure α-alkyldeoxybenzoins within a water-soluble organic capsule

Revathy Kulasekharan, Murthy V S N Maddipatla, Anand Parthasarathy, Vaidhyanathan Ramamurthy

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Optically pure α-alkyl deoxybenzoins resulting in products of Norrish Type I and Type II reactions upon excitation has been investigated within the octa acid (OA) capsule in water. The product distribution was different from that in an organic solvent and was also dependent on the length of the α-alkyl chain. Most importantly, a rearrangement product not formed in an organic solvent arising from the triplet radical pair generated by Norrish Type I reaction was formed, and its yield was dependent on the alkyl chain length. In an organic solvent, since the cage lifetime is shorter than the time required for intersystem crossing (ISC) of the triplet radical pair to the singlet radical pair the recombination with or without rearrangement of the primary radical pair (phenylacetyl and benzyl) does not occur. Recombination without rearrangement within the capsule as inferred from monitoring the racemization of the optically pure α-alkyl deoxybenzoins suggesting the capsule's stability for at least 10-8 s (the time required for ISC) is consistent with our previous photophysical studies that showed partial opening and closing of the capsule in the time range of microseconds.

Original languageEnglish
Pages (from-to)942-949
Number of pages8
JournalJournal of Organic Chemistry
Volume78
Issue number3
DOIs
StatePublished - Feb 1 2013

Fingerprint

Capsules
Organic solvents
Water
Chain length
Acids
Monitoring

ASJC Scopus subject areas

  • Organic Chemistry

Cite this

Role of free space and conformational control on photoproduct selectivity of optically pure α-alkyldeoxybenzoins within a water-soluble organic capsule. / Kulasekharan, Revathy; Maddipatla, Murthy V S N; Parthasarathy, Anand; Ramamurthy, Vaidhyanathan.

In: Journal of Organic Chemistry, Vol. 78, No. 3, 01.02.2013, p. 942-949.

Research output: Contribution to journalArticle

@article{47118209b88f4c19a3756b5df58a8373,
title = "Role of free space and conformational control on photoproduct selectivity of optically pure α-alkyldeoxybenzoins within a water-soluble organic capsule",
abstract = "Optically pure α-alkyl deoxybenzoins resulting in products of Norrish Type I and Type II reactions upon excitation has been investigated within the octa acid (OA) capsule in water. The product distribution was different from that in an organic solvent and was also dependent on the length of the α-alkyl chain. Most importantly, a rearrangement product not formed in an organic solvent arising from the triplet radical pair generated by Norrish Type I reaction was formed, and its yield was dependent on the alkyl chain length. In an organic solvent, since the cage lifetime is shorter than the time required for intersystem crossing (ISC) of the triplet radical pair to the singlet radical pair the recombination with or without rearrangement of the primary radical pair (phenylacetyl and benzyl) does not occur. Recombination without rearrangement within the capsule as inferred from monitoring the racemization of the optically pure α-alkyl deoxybenzoins suggesting the capsule's stability for at least 10-8 s (the time required for ISC) is consistent with our previous photophysical studies that showed partial opening and closing of the capsule in the time range of microseconds.",
author = "Revathy Kulasekharan and Maddipatla, {Murthy V S N} and Anand Parthasarathy and Vaidhyanathan Ramamurthy",
year = "2013",
month = "2",
day = "1",
doi = "10.1021/jo3023928",
language = "English",
volume = "78",
pages = "942--949",
journal = "Journal of Organic Chemistry",
issn = "0022-3263",
publisher = "American Chemical Society",
number = "3",

}

TY - JOUR

T1 - Role of free space and conformational control on photoproduct selectivity of optically pure α-alkyldeoxybenzoins within a water-soluble organic capsule

AU - Kulasekharan, Revathy

AU - Maddipatla, Murthy V S N

AU - Parthasarathy, Anand

AU - Ramamurthy, Vaidhyanathan

PY - 2013/2/1

Y1 - 2013/2/1

N2 - Optically pure α-alkyl deoxybenzoins resulting in products of Norrish Type I and Type II reactions upon excitation has been investigated within the octa acid (OA) capsule in water. The product distribution was different from that in an organic solvent and was also dependent on the length of the α-alkyl chain. Most importantly, a rearrangement product not formed in an organic solvent arising from the triplet radical pair generated by Norrish Type I reaction was formed, and its yield was dependent on the alkyl chain length. In an organic solvent, since the cage lifetime is shorter than the time required for intersystem crossing (ISC) of the triplet radical pair to the singlet radical pair the recombination with or without rearrangement of the primary radical pair (phenylacetyl and benzyl) does not occur. Recombination without rearrangement within the capsule as inferred from monitoring the racemization of the optically pure α-alkyl deoxybenzoins suggesting the capsule's stability for at least 10-8 s (the time required for ISC) is consistent with our previous photophysical studies that showed partial opening and closing of the capsule in the time range of microseconds.

AB - Optically pure α-alkyl deoxybenzoins resulting in products of Norrish Type I and Type II reactions upon excitation has been investigated within the octa acid (OA) capsule in water. The product distribution was different from that in an organic solvent and was also dependent on the length of the α-alkyl chain. Most importantly, a rearrangement product not formed in an organic solvent arising from the triplet radical pair generated by Norrish Type I reaction was formed, and its yield was dependent on the alkyl chain length. In an organic solvent, since the cage lifetime is shorter than the time required for intersystem crossing (ISC) of the triplet radical pair to the singlet radical pair the recombination with or without rearrangement of the primary radical pair (phenylacetyl and benzyl) does not occur. Recombination without rearrangement within the capsule as inferred from monitoring the racemization of the optically pure α-alkyl deoxybenzoins suggesting the capsule's stability for at least 10-8 s (the time required for ISC) is consistent with our previous photophysical studies that showed partial opening and closing of the capsule in the time range of microseconds.

UR - http://www.scopus.com/inward/record.url?scp=84873403576&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84873403576&partnerID=8YFLogxK

U2 - 10.1021/jo3023928

DO - 10.1021/jo3023928

M3 - Article

VL - 78

SP - 942

EP - 949

JO - Journal of Organic Chemistry

JF - Journal of Organic Chemistry

SN - 0022-3263

IS - 3

ER -