Hiroyuki Hosomi

Compelled Orientational Control of the Solid-State Photodimerization of trans-Cinnamamides: Dicarboxylic Acid as a Non-covalent Linker

Abstract The 2:1 hydrogen-bonded cocrystals 1a·ox, 1a·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.

Solid-State and Solution Photolyses of Tetracyanobenzene with Benzyl Cyanides or Benzyl Alcohols

Abstract Intermolecular photoreactions of tetracyanobenzene (TCNB) with benzyl cyanide (BzCN), benzyl alcohol (BzOH) and various others were investigated in the solid state (cocrystal) and in solution. The new solid-state photocoupling reaction found for the cocrystal TCNB·BzCN, giving a stilbene derivative followed by the solution isomerization into an isoindole derivative, is a very limited reaction. On the other hand, its solution photocondensation to give products of the diphenylmethane type occurred quite generally, probably under acidic conditions.

Ammonium and Isopropylammonium Salts of the Fumaric Acid Dianion

The crystal structures of diammonium fumarate, 2NH 4 + .C 4 H 2 O 4 2- , (I), and bis(isopropylammonium) fumarate, 2C 3 H 7 NH 3 + .C 4 H 2 O 4 2- , (II), have been determined. The intermolecular N-H...O hydrogen bonds form a three-dimensional network in (I), whereas two-dimensional sheets are formed in (II) separated by layers of isopropyl groups. The N...O distances are 2.790 (1)-2.903 (1) A in (I) and 2.747 (1)-2.807(1)A in (II). Differences between the solid-state photoreactivities of the fumaric acid ions in (I) and (II) are rationalized based on the crystal structures.

cis-Diaquabis(trans-cinnamato-O,O')zinc(II).

The title complex, [Zn(C(9)H(7)O(2))(2)(H(2)O)(2)], shows a distorted octahedral coordination and has a crystallographic twofold rotation axis. Intermolecular O-H.O hydrogen bonding forms a two-dimensional network in the ab plane.

Charge-transfer complexes of N-methyl-, N-isopropyl-, N-butyl- and N-isobutylcarbazole with 3,5-dinitrobenzoic acid.

In the title four compounds, C(13)H(11)N.C(7)H(4)N(2)O(6), (I), C(15)H(15)N.C(7)H(4)N(2)O(6), (II), C(16)H(17)N.C(7)H(4)N(2)O(6), (III), and C(16)H(17)N.C(7)H(4)N(2)O(6), (IV), the donor and acceptor molecules are stacked alternately to form one-dimensional columns. In (I), the N-methyl group of the donor is nearly eclipsed with respect to one of the nitro groups of the neighboring acceptor in a column, whereas the N-isopropyl, N-butyl and N-isobutyl groups are in anti positions with respect to one of the nitro groups of the neighboring acceptor in compounds (II)-(IV).

Selective dioxygenation of cyclohexane catalysed by hydrogen peroxide and dinuclear iron(III) complexes with µ-alkoxo bridges†

Several dinuclear iron(III) complexes with µ-alkoxo bridges gave predominantly cyclohexyl hydroperoxide in the reaction with cyclohexane and hydrogen peroxide, and similar results were observed when linear n-alkanes, such as n-nonane and n-octane, were used instead of cyclohexane. A mechanism for selective formation of the hydroperoxide is discussed.

Charge-transfer complexes of 4-(dimethylamino)pyridine with 2,4-, 3,4- and 3,5-dinitrobenzoic acid.

In the three title crystal structures 4-(dimethylamino)pyridinium 2,4-dinitrobenzoate, (I), 4-(dimethylamino)pyridinium 3,4-dinitrobenzoate, (II), and 4-(dimethylamino)pyridinium 3,5-dinitrobenzoate, (III), all C(7)H(11)N(2)(+).C(7)H(3)N(2)O(6)(-), the ions are connected by an N-H.O hydrogen bond. Dihedral angles between the pyridine and phenyl rings are 69.9 (1), 26.7 (1) and 56.2 (1) degrees in (I), (II) and (III), respectively. Donor-acceptor pi-pi stacking is observed in (II) and (III), but not in (I).

Bis(2-methylbenzyl cyanide) Tetracyanobenzene

In the title two-component crystal, the tetracyanobenzene (TCNB) molecule has a crystallographic center of symmetry, and is sandwiched by 2-methylbenzylcyanide (MeBzCN) molecules. The absence of photochemical reactivity in the solid state may be attributed to the absence of a short contact between the benzyl H atoms of MeBzCN and the cyano N atoms of TCNB, the shortest distance being 3.45 (1) A within the sandwich.

Charge-transfer complexes of N-methyl-and N-ethylcarbazole with 3,5-dinitrobenzonitrile.

In the two title compounds, N-methylcarbazole-3,5-dinitrobenzonitrile (1/1), C(13)H(11)N.C(7)H(3)N(3)O(4), (I), and N-ethylcarbazole-3,5-dinitrobenzonitrile (1/1), C(14)H(13)N.C(7)H(3)N(3)O(4), (II), the donor and acceptor molecules are stacked alternately to form one-dimensional columns. In (I), the N-methyl group of the donor is nearly eclipsed with respect to one of the nitro groups of the neighboring acceptor in a column, whereas the N-ethyl group is anti with respect to the cyano group of the neighboring acceptor in (II).

1,3-Propanediammonium bis(3'-nitro-trans-cinnamate) and trans-1,2-cyclohexanediammonium bis(3'-nitro-trans-cinnamate).

In the title two adducts, C(3)H(12)N(2)(2+).2C(9)H(6)NO(4)(-), (I), and C(6)H(16)N(2)(2+).2C(9)H(6)NO(4)(-), (II), hydrogen bonds between the diammonium and carboxylate ions form a two-dimensional network parallel to the ab plane in (I) and one-dimensional chains along the c axis in (II). The cyclohexanediammonium ion in (II) has a crystallographic twofold axis.