The molecular and crystal structure of 8-hydroxyquinoline N-oxide

Abstract

The structure of 8-hydroxyquinoline-N-oxide was determined from diffractometer data by a direct method. The compound crystallizes in the monoclinic system with space group P21/c. The cell data are: a= 12.1364 (4), b=4.9211 (2), c= 13"1384 (4) /~, fl= I09"26 (1) °, Dealt= 1-449 g.cm -a, De,,p= 1.46 g.cm -3, Z= 4. The structure was solved by a direct method. A total of 1528 reflections were used in a full-matrix least-squares refinement. R was reduced to a final value of 0.053. Bond lengths between non-hydrogen atoms have e.s.d.'s between 0.002 and 0.003 A. The e.s.d.'s of the various bond angles (non-hydrogen atoms) range from 0"01 to 0"02 °. Distances and angles involving the hydrogen atoms have e.s.d.'s of 0.02/~ and 1 °, respectively. The two C-N distances of the quinoline ring are unusually long and the quinoline moiety is surprisingly similar to naphthalene in terms of bond distances and angles. It is believed that the inductive effect of the N-O group may in part be responsible for the C-N lengthenings. The hydroxyl hydrogen atom is bonded to the dative oxygen atom via a short intramolecular hydrogen bond. The direct relationship between the N-O dative bond distance and the strength of a hydrogen bond to the dative oxygen atom appears to be substantiated in this study.

2,6-Dicarboxypyridine N-oxide

“…Similarly, the C-N bond length in pyridine Noxide is longer than in pyridine (Snerling, Nielsen, Nygaard, Pedersen & Sorensen, 1975). These effects are consistent with the observations made by Desiderato, Terry & Freeman (1971) for 8-hydroxyquinoline N-oxide and with their suggestion that it is the N-oxide group which may be responsible for the C-N lengthening. The values characteristic of the geometric features of the carboxyl group agree with those given by Leiserowitz (1976).…”

Structure of 1,8-dimethyl-4-oxo-1,2,2a,3,4,5-hexahydrocyclopenta[de]quinoline

“…N1--C2 and N1---C8a distances are shorter than the normally expected values. Similar shortening is found to occur in the quinoline ring of other structures, namely, 8-hydroxyquinoline N-oxide (Desiderato, Terry & Freeman, 1971), copper 8-hydroxyquinolinate (Palenik, 1964a), zinc 8-hydroxyquinolinate dihydrate (Palenik, 1964b) 5-acetoxy-6-methoxy-8-nitroquinoline (Sax & Desiderato, 1967) and 6-methoxy-8-nitro-5(1H)-quinolone (Sax, Desiderato & Dakin, 1969).…”

Hydrogen bonds in quinoline N-oxide derivatives: first-principle molecular dynamics and metadynamics ground state study

“…First-principle molecular dynamics within the framework of Car-Parrinello (CPMD) [1] was performed for two quinoline N-oxide derivatives: 8-hydroxyquinoline N-oxide (1) and 2-carboxyquinoline N-oxide (2) [13,14]. The models used for CPMD computations are presented in Figure S1 of the Online Resource.…”

“…The two quinoline N-oxides [8-hydroxyquinoline N-oxide (denoted as 1) and 2-carboxyquinoline N-oxide (denoted as 2)] chosen for the study are presented in Fig. 1, while their crystal unit cells are presented in the Figure S1 of the Online Resource [13,14]. They possess two kinds of hydrogen bonding.…”