Structures and Photochemistry of Inclusion Compounds of 9,10-Dihydro-9,10-ethenoanthracene-11,12-bis(diphenylmethanol)

1997 ◽  
Vol 53 (2) ◽  
pp. 300-305 ◽  
Author(s):  
T. Y. Fu ◽  
J. R. Scheffer ◽  
J. Trotter

Crystal structures have been determined for inclusion complexes of the host molecule 9,10-dihydro-9,10-ethenoanthracene-11,12-bis(diphenylmethanol), with acetone, ethanol and toluene as guest solvent molecules. The host molecule exhibits an intramolecular O--H...O hydrogen bond in each of the complexes, with intermolecular hydrogen bonds to the acetone and ethanol guests. Different photoproducts are obtained from solution and solid-state photolyses; the solid-state reaction involves a relatively small amount of molecular rearrangement, for which a mechanism is proposed.

1997 ◽  
Vol 53 (2) ◽  
pp. 293-299 ◽  
Author(s):  
T. Y. Fu ◽  
Z. Liu ◽  
G. Olovsson ◽  
J. R. Scheffer ◽  
J. Trotter

Inclusion complexes of 9,10-dihydro-9,10-etheno-anthracene-11,12-bis(diphenylphosphine oxide) (1) as host are synthesized using a variety of guest solvent molecules and the photochemistry of the host molecule is studied in solution and in the crystalline complexes. The crystal structures of four complexes are determined and correlated with their photochemical reactivity. In each case only one dibenzosemibullvalene photoproduct is obtained in the photolysis. Since three of the complexes studied crystallize in the chiral space group P212121, irradiation of single crystals produces a chiral photoproduct in >90% enantiomeric excess. Determination of the absolute configurations of reactants and products allows elucidation of the key structural features that control the enantiospecific solid-state photorearrangements.


2000 ◽  
Vol 55 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Teresa Borowiak ◽  
Irena Wolska ◽  
Artur Korzański ◽  
Wolfgang Milius ◽  
Wolfgang Schnick ◽  
...  

The crystal structures of two compounds containing enaminone heterodiene systems and forming intermolecular hydrogen bonds N-H·O are reported: 1) 3-ethoxycarbonyl-2-methyl-4-pyridone (hereafter ETPY) and 2) 3-ethoxycarbonyl-2-phenyl-6-methoxycarbonyl-5,6-di-hydro-4-pyridone (hereafter EPPY). The crystal packing is controlled by intermolecular hydro­ gen bonds N-H·O = C connecting the heteroconjugated enaminone groups in infinite chains. In ETPY crystals the intermolecular hydrogen bond involves the heterodienic pathway with the highest π-delocalization that is effective for a very short N·O distance of 2.701(9) Å (average from two molecules in the asymmetric unit). Probably due to the steric hindrance, the hydrogen bond in EPPY is formed following the heterodienic pathway that involves the ester C = O group, although π-delocalization along this pathway is less than that along the pyridone-part pathway resulting in a longer N·O distance of 2.886(3) Å


2017 ◽  
Vol 73 (8) ◽  
pp. 1259-1263 ◽  
Author(s):  
Rakesh Ganguly ◽  
Violeta Jevtovic

Reaction of BI3 with carbodiphosphorane, C(PPh3)2, gives a mixture of the dicationic compounds, methylenebis(triphenylphosphonium) diiodide dichloromethane disolvate, C37H32P2 2+·2I−·2CH2Cl2 or [Ph3PCH2PPh3]I2·2CH2Cl2 (I), methylenebis(triphenylphosphonium) bis(tetraiodoborate), C37H32P2 2+·2BI4 − or [Ph3PCH2PPh3](BI4)2 (II). Solvents are the source of the protons at the ylidic C atom. The P—C—P angle is 124.1 (2)° for (I) and 121.7 (3)° for (II), while the two P—C bond lengths are 1.804 (4) and 1.807 (5) Å in (I), and 1.817 (5) and 1.829 (5) Å in (II). In the crystal of (I), the protons of the central P—CH2—P C atom exhibit weak C—H...I hydrogen bonds with the respective anions. The anions in turn are linked to the dichloromethane solvent molecules by C—H...I hydrogen bonds. In the crystal of (II), one of the BI4 − anions is linked to a phenyl H atom via a weak C—H...I hydrogen bond.


Author(s):  
Agnieszka Czapik ◽  
Marcin Kwit

The structure of N-triphenylacetyl-L-tyrosine (C29H25NO4, L-TrCOTyr) is characterized by the presence of both donors and acceptors of classical hydrogen bonds. At the same time, the molecule contains a sterically demanding and hydrophobic trityl group capable of participating in π-electron interactions. Due to its large volume, the trityl group may favour the formation of structural voids in the crystals, which can be filled with guest molecules. In this article, we present the crystal structures of a series of N-triphenylacetyl-L-tyrosine solvates with chloroform, namely, L-TrCOTyr·CHCl3 (I) and L-TrCOTyr·1.5CHCl3 (III), and dichloromethane, namely, L-TrCOTyr·CH2Cl2 (II) and L-TrCOTyr·0.1CH2Cl2 (IV). To complement the topic, we also decided to use the racemic amide N-triphenylacetyl-DL-tyrosine (rac-TrCOTyr) and recrystallized it from a mixture of chloroform and dichloromethane. As a result, rac-TrCOTyr·1.5CHCl3 (V) was obtained. In the crystal structures, the amide molecules interact with each other via O—H...O hydrogen bonds. Noticeably, the amide N—H group does not participate in the formation of intermolecular hydrogen bonds. Channels are formed between the TrCOTyr molecules and these are filled with solvent molecules. Additionally, in the crystals of III and V, there are structural voids that are occupied by chloroform molecules. Structure analysis has shown that solvates I and II are isostructural. Upon loss of solvent, the solvates transform into the solvent-free form of TrCOTyr, as confirmed by thermogravimetric analysis, differential scanning calorimetry and powder X-ray diffraction.


1993 ◽  
Vol 48 (7) ◽  
pp. 1023-1026 ◽  
Author(s):  
Christer B. Aakeröy ◽  
Kenneth R. Seddon

A reinvestigation of the previously determined structures of two polymorphs of pyridinium chloride shows that both polymorphs contain several aromatic C– H-H···Cl hydrogen-bond interactions. These hydrogen bonds, hitherto unrecognized, may play a significant structural role, both in solution and in the solid-state.


2000 ◽  
Vol 56 (6) ◽  
pp. 1094-1102 ◽  
Author(s):  
Carl Henrik Görbitz ◽  
Hans-Petter Hersleth

Useful information about hydrogen bonding, the preferred modes of hydrophobic interaction and conformational preferences of a specific molecule can be obtained from cocrystallization of the solute with a selected series of solvent molecules. This method is used in a study of nine different crystal structures of diethylstilbestrol (DES) solvates. It is shown that solvent inclusion results not only in stronger hydrogen bonds, but usually also in a larger number of favorable C—H...π interactions between DES molecules. Furthermore, solvent molecules such as DMSO, DMF, acetonitrile and acetone demonstrate important hydrogen-bond donating properties in addition to their more familiar role as hydrogen-bond acceptors. Molecular conformations in the crystal structures compare favorably with results from molecular mechanics calculations.


1999 ◽  
Vol 54 (5) ◽  
pp. 643-648 ◽  
Author(s):  
Karna Wijaya ◽  
Oliver Moers ◽  
Armand Blaschette ◽  
Peter G. Jones

The compounds (2-pyridone)2H+(MeSO2)2N- (1, monoclinic, space group P21/n ) and (6- methyl-2-pyridone)2H+(MeSO2)2N- (2, triclinic, P1) crystallize selectively and in good yields when the parent 2-pyridones (2-hydroxypyridines) are treated with the strong NH acid dimesylamine in acetonitrile or acetone. The corresponding 2-hydroxypyridinium salts could not be obtained. In the unprecedented crystal structures of 1 and 2, two pyridone units are linked by a proton to form very short and approximately symmetric O⋯H+ ⋯O hydrogen bonds, the adjacent C-O distances being appreciably elongated as compared to “free” pyridones [1: O ⋯ O 241.8(2), C -O 127.8(3) and 129.1(2) pm; 2: O ⋯ O 243.8(2), C -O 128.1(2) and 129.2(2) pm]. In both crystal packings, the homoconjugate cations and the dimesylamide anions are alternately associated into chains by an N - H ⋯ N “ and an N - H ⋯ O hydrogen bond.


2021 ◽  
Vol 44 (1) ◽  
pp. 213-217
Author(s):  
Waly Diallo ◽  
Hélène Cattey ◽  
Laurent Plasseraud

Abstract Crystallization of [(Ph3Sn)2SeO4] ⋅ 1.5H2O in methanol leads to the formation of [{(Ph3Sn)2SeO4} ⋅ CH3OH] n (1) which constitutes a new specimen of organotin(IV) selenate derivatives. In the solid state, complex 1 is arranged in polymeric zig-zag chains, composed of alternating Ph3Sn and SeO4 groups. In addition, pendant Ph3Sn ⋅ CH3OH moieties are branched along chains according to a syndiotactic organization and via Sn-O-Se connections. From a supramolecular point of view, intermolecular hydrogen bonds established between the selenate groups (uncoordinated oxygen) and the hydroxyl functions (CH3OH) of the pendant groups link the chains together.


1980 ◽  
Vol 35 (2) ◽  
pp. 237-238 ◽  
Author(s):  
Martin Jansen

Abstract K3NO3 and RbsNO3 were prepared by solid state reaction of equimolar mixtures of K2O/KNO2 and Rb20/RbN02, respectively. According to X-ray powder photographs their crystal structures are derived from the perovs-kite structure. K3NO3 is isostructural with Na3NO3 (a = 521.7 pm, Z = 1), Rb3NO3 represents a tetragonally distorted variant with a = 770.5, c = 550.8 pm and Z = 2.


2013 ◽  
Vol 69 (2) ◽  
pp. m73-m74 ◽  
Author(s):  
Sigurd Øien ◽  
David Stephen Wragg ◽  
Karl Petter Lillerud ◽  
Mats Tilset

In the title compound, [Cu2Cl4(C12H8N2O4)2]·4C3H7NO, which contains a chloride-bridged centrosymmetric CuIIdimer, the CuIIatom is in a distorted square-pyramidal 4 + 1 coordination geometry defined by the N atoms of the chelating 2,2′-bipyridine ligand, a terminal chloride and two bridging chloride ligands. Of the two independent dimethylformamide molecules, one is hydrogen bonded to a single –COOH group, while one links two adjacent –COOH groupsviaa strong accepted O—H...O and a weak donated C(O)—H...O hydrogen bond. Two of these last molecules and the two –COOH groups form a centrosymmetric hydrogen-bonded ring in which the CH=O and the –COOH groups by disorder adopt two alternate orientations in a 0.44:0.56 ratio. These hydrogen bonds link the CuIIcomplex molecules and the dimethylformamide solvent molecules into infinite chains along [-111]. Slipped π–π stacking interactions between two centrosymmetric pyridine rings (centroid–centroid distance = 3.63 Å) contribute to the coherence of the structure along [0-11].


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