A double [2 + 2] photochemical reaction of 1,5-bis(4-pyridyl)-1,4-pentadiene-3-one (1P) was observed with in four co-crystal forms of 1P with the hydrogen bonding template molecule phloroglucinol (PG) or 5-methoxy resorcinol (MR). 1H NMR and the UV-vis spectroscopic studies established a stepwise mechanism for this reaction through the formation of a monocyclobutane intermediate.
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Solid state double [2 + 2] photochemical reactions in the co-crystal forms of 1,5-bis(4-pyridyl)-1,4-pentadiene-3-one: establishing mechanism using single crystal X-ray, UV and 1H NMR
Ramkinkar Santra and Kumar Biradha
CrystEngComm, 2011, Advance Article