scholarly journals A trigonal coordination of Au(I) phosphane complexes stabilized by O–H⋯X (X = Cl–, Br–, I–) interactions

Author(s):  
Petra Gründlinger ◽  
Cezarina Cela Mardare ◽  
Thorsten Wagner ◽  
Uwe Monkowius

AbstractIn this work, we show that intramolecular hydrogen bonding can be used to stabilize tri-coordinated phosphane-gold(I) complexes. Two molecular structures of 2-(diphenylphosphino)benzoic acid (L) coordinated to a gold(I) atom were determined by single-crystal X-ray diffraction. The linear L–Au–Br shows a standard linear coordination and dimerizes via hydrogen bonds of the carboxylic acid. Upon addition of two additional phosphane ligands the complex [L3Au]X is formed which is stabilized by three intramolecular –C(O)O–H…X hydrogen bonds as proven by the X-ray structure of the respective chlorido-complex. X-ray powder diffractograms suggest the same structure also for X– = Br– and I–. Graphic abstract

2007 ◽  
Vol 63 (2) ◽  
pp. 303-308 ◽  
Author(s):  
Andrew Parkin ◽  
Martin Adam ◽  
Richard I. Cooper ◽  
Derek S. Middlemiss ◽  
Chick C. Wilson

A new polymorph of 2,4-dihydroxybenzoic acid is reported. The structure was characterized by multiple-temperature X-ray diffraction and solid-state DFT computations. The material shows a geometric pattern of hydrogen bonding consistent with cooperativity between the intermolecular carboxylic acid dimer and intramolecular hydrogen bonds. The presence of proton disorder within this hydrogen-bond system, which would support such a cooperative model, was not fully ruled out by the initial X-ray studies. However, solid-state calculations on the three possible end-point tautomers indicate that the dominant crystallographically observed configuration is substantially lower in energy than the other tautomers (by at least 9 kJ mol−1), indicating that no disorder should be expected. It is therefore concluded that no disorder is observed either in the intra- or intermolecular hydrogen bonds of the title compound and that the cooperativity between the hydrogen bonds is not present within the temperature range studied.


1983 ◽  
Vol 36 (10) ◽  
pp. 2073 ◽  
Author(s):  
H Becker ◽  
BW Skelton ◽  
AH White

The structures of two isomeric 3,5-di-t-butyl-2-[(3,5-di-t-butyl-2-hydroxyphenyl){(Z)-methylimino}- methyl]cyclopent-2-en-1-ones, formed upon photoexcitation of 3,5-di-t-butyl-7-(3,5-di-t-butyl-2- hydroxyphenyl)-1-methyl-1H-azepin-2(3H)-one in methanol, have been established by X-ray diffraction, and are found to be examples of atropisomeric ketimines. In both isomers, the geometry of imino substitution is characterized by intramolecular hydrogen bonding with the phenolic hydroxyl.


1992 ◽  
Vol 47 (8) ◽  
pp. 1141-1153 ◽  
Author(s):  
Sven M. Jessen ◽  
Horst Küppers ◽  
Dean C. Luehrs

Four acid salts of pyromellitic acid (benzene-1,2,4,5-tetracarboxylic acid) have been synthesized and studied by X-ray diffraction and IR spectroscopy. (1) Dilithium dihydrogen pyromellitate pentahydrate, Li2[C6H2(COO)4H2]· 5H2O; monoclinic, P21/m, a = 6.214(2), b = 19.647(7), c = 6.592(2)Å, β = 115.90(2)°, Ζ = 2, R = 0.068, Rw = 0.067. (2) Hexaaquanickel dihydrogen pyromellitate, [Ni(H2O)6][C6H2(COO)4H2]; monoclinic, P2/m, a = 6.528(1), b = 9.927(2), c = 6.472(1)Å, β = 115.57(1)°, Z = 1, R = 0.044, Rw = 0.039. (3) Tetrabutylammonium trihydrogen pyromellitate, [(C4H9)4N][C6H2(COO)4H3]; monoclinic, P21/c, a = 9.719(4), b = 18.823(8), c = 15.795(5)Å, β = 107.42(3)°, Z = 4, R = 0.059, Rw = 0.039. (4) Diammonium dihydrogen pyromellitate, [NH4]2[C6H2(COO)4H2]; monoclinic, P21/c, a = 4.7665(6), b = 11.681(3), c = 10.149(2)Å, ß = 102.19(2)°, Z = 2, R = 0.045, Rw = 0.039. Compounds 1, 2, and 3 show very short intramolecular hydrogen bonds between adjacent carboxylic groups (O ••• O distances 2.384(6), 2.386(5), 2.387(3)Å, respectively). Compound 4 forms intermolecular hydrogen bonds (O ··· O distance 2.642(2) A). The different hydrogen bonding modes are also evident in the IR spectra.


1995 ◽  
Vol 91 (1) ◽  
pp. 77 ◽  
Author(s):  
Krzysztof Wozniak ◽  
Heyong He ◽  
Jacek Klinowski ◽  
William Jones ◽  
Teresa Dziembowska ◽  
...  

1984 ◽  
Vol 62 (3) ◽  
pp. 526-530 ◽  
Author(s):  
Michel Baron ◽  
Sylviane Giorgi-Renault ◽  
Jean Renault ◽  
Patrick Mailliet ◽  
Daniel Carré ◽  
...  

Butanedione reacts on heating with 1,2-diaminoanthraquinone to give, not the expected 2,3-dimethyl-naphtho[2,3-f]quinoxaline-7,12-dione 3, but 2-(2-hydroxy-2-methyl-3-oxobutyl)-3-methylnaphtho[2,3-f]quinoxaline-7,12-dione 4a whose structure was established by X-ray diffraction. This compound crystallizes in the triclinic [Formula: see text] space group with unit cell dimensions of a = 9.091 (1), b = 16.966 (4), c = 12.375 (3) Å; α = 100.75 (2), β = 101.83 (2), γ = 100.29 (2)°, V = 1789 Å3, Z = 4. The structure was resolved by the direct method and refined to R = 0.039 for 3027 independent reflections. The overall conformation of the molecule is essentially planar. The principal characteristic is the presence of two cyclic arrangements caused by intramolecular hydrogen bonding. 2,3-Dimethylnaphtho[2,3-f]quinoxaline-7,12-dione is the intermediate in this reaction.


Author(s):  
F. J. Martínez-Martínez ◽  
I. I. Padilla-Martínez ◽  
M. A. Brito ◽  
E. D. Geniz ◽  
R. C. Rojas ◽  
...  

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