36650-35-8Relevant academic research and scientific papers
Compelled orientational control of the solid-state photodimerization of trans-cinnamamides: Dicarboxylic acid as a non-covalent linker
Ito, Yoshikatsu,Hosomi, Hiroyuki,Ohba, Shigeru
, p. 6833 - 6844 (2007/10/03)
The 2:1 hydrogen-bonded cocrystals 1a·ox, la·su, 1a·pht, 1a·fu, 1b·ox, 1c·ox, 1d·ox between trans-cinnamamides (1a-1d) and dicarboxylic acids (ox, su, gl, fu, pht) were prepared and characterized by IR and powder X-ray techniques. The crystal structures of 1a·pht, 1a·ox and 1a·fu were solved by single crystal X-ray diffraction. Phthalic acid (pht) caused β-type photodimerization of trans-cinnamamide (1a) in the cocrystal and functioned as a non-covalent linker like gauche 1,2-diamines in photodimerization of trans-cinnamic acids. Oxalic acid (ox) enforced 1a to take a bilayer structure that is suitable for β-type photodimerization. In the case of fumaric acid (fu), cross photodimerization with 1a occurred to give a cycloadduct 4. For the cocrystals 1a·pht and 1a·fu, pedal-like motion was assumed to occur prior to the dimerization. (C) 2000 Elsevier Science Ltd.
Crystal-to-crystal photodimerization of trans-cinnamamides
Hosomi, Hiroyuki,Ito, Yoshikatsu,Ohba, Shigeru
, p. 682 - 689 (2007/10/03)
In the crystals of trans-4-methylcinnamamide, C10H11NO (I), trans-4-chlorocinnamamide, C9H8ClNO (II), trans-3-(2-thienyl)acrylamide, C7H7NOS (III), and trans-cinnamamide, C9H9NO (IV), the shortest intermolecular C...C distances between the C=C double bonds are 3.670 (2), 3.632 (2), 3.762 (3) and 4.120 (2) A, respectively, for the pair of molecules related by a center of symmetry. The structure analysis was also carried out for trans-2-(p-chlorophenyl)-cis-4-(p-chlorophenyl)-1-trans-3-diamidocyclobutane, C18H16Cl2-N2O2 (V), which is the α-type photodimer of (II). The N -H...O hydrogen-bond networks in (I)-(III) are composed of two-dimensional pleated sheets, and those in (IV) and (V) of one-dimensional flat ribbons. The single crystals of (I), (II) and (IV) were photoirradiated with a 250 W ultra-high-pressure mercury lamp through a band-pass filter or a long-pass filter for 2-5 h. The photodimer was produced in each crystal with retention of the single-crystal form. The populations of the dimers were converged to 86.2 (4), 48.4 (6) and 4.5 (2)% in the refinement of the crystals after photoirradiation, (I′), (II′) and (IV′), respectively. Although the intermolecular N-H...O hydrogen-bond network remained in (I′) and (II′), the network was partly broken in (IV′) in the process of photoreaction.
