@article{2928547,
    title = "A Regiocontrolled `Head-to-Tail' [2+2] Photodimerization of a Stilbene involving a Ternary Solid based on Catechol",
    author = "Giannis S. Papaefstathiou and Tomislav Friščic and Leonard R. MacGillivray",
    journal = "Journal of Supramolecular Chemistry",
    year = "2002",
    volume = "2",
    number = "1-3",
    pages = "227--231",
    publisher = "ELSEVIER BV",
    issn = "1472-7862",
    doi = "10.1016/s1472-7862(03)00077-7",
    keywords = "linear templates, photodimerization",
    abstract = "Co-crystallization of 1,2-dihydroxybenzene (cat) with trans-1-(2-pyridyl)-2-(4-pyridyl)ethylene (2,4-bpe) gives a layered ternary solid, (cat)·(2,4-bpe)·(H2O) 1, with molecular components held together by a combination of O–H⋯N and O–H⋯O forces wherein 2,4-bpe is organized for a ‘head-to-tail’ (ht) [2+2] photocyclodimerization. UV-irradiation of the solid produces rctt-1,3-bis(2-pyridyl)-2,4-bis(4-pyridyl)cyclobutane [rctt-(2,4-tpcb-ht)] in quantitative yield. The structure of rctt-(2,4-tpcb-ht), in the form of crystalline rctt-(2,4-tpcb-ht)·1.5(H2O), has been confirmed by way of single-crystal X-ray diffraction."
}