Separation of phenol and cresols by crystalline complexation with 1,1-di(p-hydroxyphenyl)cyclohexane,and crystal structure analyses of the complexes

This paper is concerned with 11 inclusion complexes of the 1,1-di(p-hydroxyphenyl)cyclohexane host with either phenol or one of the cresol derivatives as guest. Selectivity studies showed preferential complexation with a guest according to the sequence;m-cresol > p-cresol > phenol > o-cresol. Crystallographic analyses of the four complexes revealed isomorphous structures [crystal data for the phenol complex:a=6.232,b=10.849,c=14.845 Å, =95.69, =93.49, =104.31°, space groupPl,Z=2]. The intermolecular arrangements are characterized by layers of efficiently hydrogen bonded entities (host-to-host, host-to-guest and guest-to-host) parallel toab, every OH group being involved in two H-bonds. Organization of the layers alongc is stabilized by weak dispersion forces, thus being most sensitive to structural variation of the guest component. The observed features of selectivity upon crystalline complexation are related to differences in topological complementarity between the constituents of each structure. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82052 (4 pages).     

Complexation ofp-xylene withp-isopropylcalix[4]arene: Crystal structures and thermal analysis of the empty form and the (1 : 1) and (2 : 1) complexes

This paper concerns inclusion complexes of thep-isopropylcalix[4]arene host withp-xylene as guest. It is shown that from a saturated solution inp-xylene, the macrocycle gives a 1 : 1 complex; on heating, the 1 : 1 complex is transformed into a 2: 1 complex, and then into the empty macrocycle. The compounds are studied by differential scanning calorimetry, thermogravimetry and X-ray powder diffraction; the three crystal structures are reported showing the arrangements of the macrocycles with and without their guests.Supplementary data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82143 (59 pages).     

Host-guest chemistry. 2. Amine inclusion compounds of 2-[o-(triphenylphosphoranylidenamino)benzyliden]amino-1H-2,3-dihydroindazol-3-one. X-ray structure of its 1∶1∶1 inclusion complex with isopropylamine and water

The crystal and molecular structure is reported for the inclusion compound 2-[o-(triphenylphosphoranylidenamino)benzyliden]amino-1H-2,3-dihydroindazol-3-one/isopropylamine/water3b. The crystal structure consists of discrete dimeric salt-like aggregates joined together by strong N⁺–H...^–O–C hydrogen bonds between pairs of centrosymmetrically-related indazolonate anions and isopropylammonium cations. Six other inclusion compounds have been prepared and characterized by NMR [with propylamine (3a), withtert-butylamine (3c), withsec-butylamine (3d), withtert-pentylamine (3e), with 1-methylbutylamine (3f) and withiso-pentylamine (3g)]. Two different arrangements are found, both with the host being in the anionic form. The guests are either: (i) one protonated amine and one water molecule (3b and3f); or (ii) one protonated amine and the corresponding neutral amine (3a, 3c, 3d, 3e and3g). Supplementary Data relating to this article (structure factors, thermal components, hydrogen parameters and bond distances and angles, and¹³C-NMR shifts) are deposited with the British Library at Boston Spa, Wetherby, West Yorkshire, U.K., as Supplementary Publication No. SUP 82155 (23 pages).For Part 1, see Reference [1].     

Flow injection-spectrophotometric determination of cresol compounds in water by reaction withp-aminophenol

A spectrophotometric method has been developed for the simultaneous determination ofo-cresol andm-cresol in water by reaction withp-aminophenol (PAP). Three different methodologies have been assayed; (i) batch analysis, after reaction in an alkaline medium in the presence of dissolved molecular oxygen as oxidizing agent, (ii) a stopped-flow procedure, carried out in the presence of KIO₄ and (iii) a flow injection method based on the same approach. The batch procedure requires 22 min for the full development of colour witho-cresol and 12 min form-cresol. In the stopped-flow mode, using KIO₄ and a reaction time of 12 min, better sensitivity can be obtained for both compounds and limits of detection of 10 g 1^–1 foro-cresol and 30 g 1^–1 form-cresol were found. The flow injection method has a lower sensitivity but permits more than 80 injections per hour. Based on the different maximum absorbance wavelengths obtained for the reaction products of PAP witho-cresol (614 nm) andm-cresol (632 nm), both compounds can be simultaneously determined in water samples and recoveries of 90 to 115% were found in spiked water samples of different types.     

Crystal structures of ethylenediaminecadmium(II) tetracyanocadmate(II)-benzene(1/2) and ethylenediaminecadmium(II) tetracyanocadmate(II)

The crystal structure of ethylenediaminecadmium(II) tetracyanocadmate(II)-benzene(1/2),I, has been redetermined based on 1632 reflections collected anew for the crystal coated with epoxy resin, with a final conventionalR=0.038;I crystallizes in space groupP4₂22, witha=b=8.265(1) andc=15.512(3) Å, andZ=2. Ethylenediaminecadmium(II) tetracyanocadmate(II),II, is concluded to be identical with the residual metal complex host ofI, remaining after the liberation of the guest benzene molecules;II crystallizes from an aqueous solution containing bis- or tris-ethylenediaminecadmium(II) tetracyanocadmate(II) in space groupI4₁/acd, witha=b=14.366(1) andc=23.771(4) Å, andZ=16; refinement led to a conventionalR=0.043 for 1181 reflections. The bridging ethylenediamine ligand inI turns to a chelating one inII; dissociation and recombination should occur in the coordination sphere of the six-coordinate cadmium atom, whenII is derived fromI by the liberation of the guest molecules. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82018 (30 pages).Dedicated to Professor H. M. Powell.     

Crystal structure analysis of the carbon tetrabromide clathrate of hexakis(phenylseleno)benzene

The 12 inclusion compound of hexakis(phenylseleno)benzene (1) with CBr₄ is trigonal, space groupR , witha=14.474(3),c=21.487(4) Å, and three host and six guest molecules in a unit cell referred to hexagonal axes. A true clathrate structure is found and in each closed cage there are two carbon tetrabromide guest molecules, orientated such that a C–Br bond of each is colinear with thec-axis of the crystal. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82002. To obtain copies, see page ii of this issue.     

Crystalline inclusion compounds of tetrabenzo-18-crown-6 with uncharged organic molecules. Solid-state structure of the nitroethane complex

Tetrabenzo-18-crown-6 (1) shows distinct solid-state inclusion properties towards a number of OH-acidic, CH-acidic and low-polar uncharged organic molecules. The single crystal X-ray analysis of the inclusion complex between1 and EtNO₂ (11) is reported. Crystals are monoclinic,P2₁/c, witha=12.887(1),b=19.365(2),c=10.776(1) Å, =96.33(2)^o,D _c=1.321g cm^–1,Z=4. The host macroring has a conformation similar to a dentist's-chair. The complex is stabilized mainly by C–H...O type interactions involving the methyl group of the EtNO₂ guest molecule which is highly disordered. The nitroethane guests are trapped in channels formed by the host macrocycles. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82150 (11 pages)     

Crystal structure of the 2:1 inclusion compound between deoxycholic acid and quadricyclane

The 2:1 inclusion compound formed between deoxycholic acid (C₂₄H₄₀O₄,M _r=392.58) and quadricyclane (C₇H₈,M _r=92.14) crystallizes in space groupP2₁2₁2₁ witha=27.150(7),b=13.359(3),c=14.161(4) Å,Z=4. The structure was refined toR=0.08₆ andR _w=0.08₈ for 2079 observed reflections withI>2.5(I). The crystal packing is very similar to that found in the norbornadiene-deoxycholic acid inclusion compound and is characterized by an assembly of antiparallel pleated bilayers, formed by molecules of deoxycholic acid held together through hydrogen bonds. Quadricyclane occupies approximately the same position of norbornadiene and its atoms give rise to good van der Waals interactions with some methyl groups of deoxycholic acid. Supplementary Data relating to the article are deposited with the British Library as Supplementary Publication No. SUP 82006 (14) pages. To obtain copies, see page ii of this issue.     

Trigonal prismatic bicyclocalixaromatics,synthesis and structures

Two trigonal prismatic bicyclooxacalixarenes 1 and 2 were obtained by condensation reaction of 1,3,5-tri(p-hydroxyphenyl)benzene and 2,4,6-tri(p-hydroxyphenyl)triazine, respectively, with 1,5-difluoro-2,4-dinitrobenzene. Single crystal structural analysis revealed that the bicyclooxacalixarene 1 adopts a distorted triangular prismatic structure. Bicyclooxacalixarene 2, however, possesses an almost D _3 h symmetric triangular prismatic structure. The colorimetric changes in the acetone solutions of 1 or 2 upon addition of certain anions have been found highly relevant to the nitro-substituents in the phenyl pillars, not to their macrocyclic structures.     

Preparation,characterization of new Co(II) and Cu(II) phthalocyanines and their catalytic performances in aerobic oxidation of substituted phenols

The host–guest inclusion complex of meta-cresol (m-cresol, liquid at room temperature, guest molecule) is synthesized with β-cyclodextrin (β-CD, host molecule). The inclusion complex is characterized by various techniques like nuclear magnetic resonance, powder X-ray diffraction, field emission scanning electron microscopy and spectroscopic (steady state as well as time-resolved) techniques. To the best of our knowledge, no literature data is available on the photophysical properties (especially fluorescence upon photoexcitation) of m-cresol in liquid media till date. Our spectroscopic studies exhibit some interesting photophysical properties of m-cresol and its inclusion complex with β-CD in different liquid media. The present work is important in view of the various potential applications of m-cresol in science, technology and medicine.     

Crystallographic studies of the molecular complexes ofE,E-1[p-dimethylaminophenyl]-5-[o-hydroxyphenyl]-penta-1,4-dien-3-one 9DHDK) with chloroform (1:0.4),m-dinitrobenzene (1:1) andp-dimethylaminobenzaldehyde (1:1); the Heilbron complexes

Crystal structures are reported for the molecular complexes ofE,E-1-[p-dimethylaminophenyl]-5-[o-hydroxyphenyl]-penta-1,4-dien-3-one (DHDK) with chloroform,m-dinitrobenzene andp-dimethylaminobenzaldehyde. The three complexes (first reported by I. M. Heilbron and J. S. Buck [1] in 1921) have different structures. In DHDK·0.4 CHCl₃ (triclinic,a=12.086(6),b=10.323(5),c=8.015(4) Å, =94.58(6), =103.58(6), =110.10(6)^o,Z=2,P (assumed)), the host molecules are linked by two hydroxyl carbonyl hydrogen bonds to form centrosymmetric pairs, with the disordered CHCl₃ molecules contained in cavities left between the molecule pairs. The complex is a clathrate. In DHDK·m-dinitrobenzene (triclinic,a=21.787(9),b-13.850(5),c=7.759(4) Å, =88.25(5), =84.70(5), =88.86(5)^o,P ,Z=4) the DHDK molecules are linked in ribbons through head-to-waist hydroxyl-carbonyl hydrogen bonds. The guest molecules are contained in sinuous channels left between the DHDK ribbons; the host and guest molecules are approximately coplanar. Successive planes are mutually shifted so that the guest molecules are enclosed above and below by host molecules. This is a new structural type, with features resembling those of channel inclusion complexes. In DHDK·p-dimethylaminobenzaldehyde (monoclinic,a=22.331(9),b=12.238(5),c=8.904(4) Å, =92.99(5)^o,Z=4,P2₁/n) the host molecules are arranged so as to leave channels of approximately rectangular cross-sections in which the guest molecules are accommodated. Additional stabilization is achieved by hydrogen bonding between host hydroxyl and guest carbonyl groups. This is a channel-inclusion complex. In the chloroform andp-dimethylaminobenzaldehyde complexes the host molecule has thes-trans, trans conformation but in them-dinitrobenzene complex its conformation iss-cis, trans.Dedicated to Professor Friedrich Cramer on the occasion of his 60th birthday Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication NO. SUP 90076 (13 pages). To obtain copies, see page ii of this issue.Molecular Compounds and Complexes, Part XIV. For Part XIII, see [25].     

Crystal structure of theβ-clathrate form of 4-p-hydroxyphenyl-2,2,4-trimethylselenachroman

In contrast top-hydroxyphenyl-2,2,4-trimethylchroman, Dianin's compound (1), or itsthia analogue2, the title seleno-ether has been found to form two crystallographically distinct types of clathrate. In the first-discovered form, the -modification of as yet undefined structure, the rhombohedral unit cell (R , a = 57.42(1) Å, c = 10.817(1) Å, [from EtOH]) has approximately four times the volume of that found in the clathrates of1 or2 and contains 72 host molecules. Recrystallisation of the selena-host fromn-hexane, however, produces another type of rhombohedral crystal: the-modification has space group R , witha=28.225(2)Å,c=10.859(1)Å, and 18 host molecules in the unit cell. A detailed X-ray study of this latter inclusion compound (host-guest ratio 6:1) has established its true clathrate nature; the disorderedn-hexane guest, showing electron density consistent with an extended planar zig-zag conformation, is found threading the hour glass-shaped cavity's central constriction. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82045 (25 pages).     

Clathrates of organic onium halides,V: preparation of new clathrates and structure of the 1-propanol inclusion of a bis-quinuclidinium salt

Organic onium salts (3–15) are prepared and their inclusion capacity towards solvent molecules is investigated. The crystal structure of the1·propanol·H₂O clathrate ofN,N-[5-tert-butyl-1,3-phenylenebis(methylene)]bis(quinuclidinium)dibromide (4) is reported and compared with the X-ray structures of related clathrates described earlier. Supplementary Data: Details of the crystal structure are available on request from the Fachinformationszentrum Energie-Physik-Mathematik, D-7517 Eggenstein, Leopoldshafen 2, by quoting the depository number CSD 50883, the names of the authors, and the journal citation.     

Chiral crystalline hosts derived from lactic acid.* X-ray crystal structures of optically resolved and racemic host compound 1,1-diphenyl-1,2-propanediol and a 2:1 complex between optically resolved host and 3-picoline

Abstract

The X-ray crystal structures of racemic (1) and S-1,1-diphenyl-1,2-propanediol (2), and of a 2:1 inclusion complex (3) of 2 with 3-picoline are reported. Three different binding schemes characterize the packing of these structures. Only one of the two hydroxy groups (that which is not related to the asymmetric carbon) is involved in O-H…O hydrogen bonds responsible for the formation of dimers and chains in 1 and 2, leaving the other OH group for stabilization of dimers through OH…phenyl interactions in 1 or free of interactions in 2. In the crystal structure of the chiral complex 3, the hydroxy groups link the two independent host molecules, A and B, the 3-picoline guest to the B host molecule, and a remaining one forms H-bonded chains along the c axis.     

Kalidoss—Jacobson Free Length Theory Applied to Binary Liquid Mixtures of CCI4+Toluene/Aniline/oCresol m-cresol p-Cresol

Abstract

Ultrasonic velocities and intermolecular free lengths in binary liquid mixtures of CC4 with toluene, aniline, o-cresol, m-cresol and p-cresol have been calculated theoretically, at different compositions and at temperature 298 K, based on Free Length Theory as revised recently by Kalidoss. It is observed that there is a close agreement of calculated velocities with experimental ones. The shape and thermostatic state picture built up in this formulation could be considered as a good representation of molecular state.     

Triol Crystalline Hosts Derived from Malic Acid. Synthesis,Inclusion Formation and X-ray Crystal Structures of a Free Host and its Inclusion Compound with Ethanol (1:1)

Abstract

Four new host compounds 1–3 (a, b) derived from malic acid as different optical species and having particular lateral substituents were synthesized. Their properties in crystalline inclusion formation were studied and discussed. Crystal structures of a free host compound 1 and its ethanol inclusion complex [1·EtOH (1:1)] have been determined by X-ray analysis [1: orthorhombic, P2₁2₁2₁, a = 9.304(3), b = 14.950(3), c = 15.712(3) Å, Dc = 1.248 Mg·m^?3, Z = 4, R = 0.039 for 2474 reflexions; 1·EtOH (1:1): triclinic, P 1; a = 11.945(3), b = 14.080(3), c = 16.029(4) Å, α = 106.82(2), β = 97.74(2), γ = 89.93(2)°, D_c = 1.187 Mg·m³, Z = 4, R = 0.096 for 10404 data]. Spontaneous resolution occurs during crystallization in crystals of 1. An interesting H-bonding pattern develops that probably is responsible for the inclusion formation with ethanol in the associate crystal.     

Nitrosation kinetics of phenolic components of foods and beverages

The kinetics of the reactions between sodium nitrite and phenol or m-, o-, or p-cresol in potassium hydrogen phthalate buffers of pH 2.5–5.7 were determined by integration of the monitored absorbance of the C-nitroso reaction products. At pH > 3, the dominant reaction was C-nitrosation through a mechanism that appears to consist of a diffusion-controlled attack on the nitrosatable substrate by NO⁺/NO₂H₂⁺ ions followed by a slow proton transfer step; the latter step is supported by the observation of basic catalysis by the buffer which does not form alternative nitrosating agents as nitrosyl compounds. The catalytic coefficients of both anionic forms of the buffer have been determined. The observed order of substrate reactivities (o-cresol ≈ m-cresol > phenol ≫ p-cresol) is explained by the hyperconjugative effect of the methyl group in o- and m-cresol, and by its blocking the para position in p-cresol. Analysis of a plot of ΔH^# against ΔS^# shows that the reaction with p-cresol differs from those with o- and m-cresol as regards the formation and decomposition of the transition state. The genotoxicity of nitrosatable phenols is compared with their reactivity with NO⁺/NO₂H₂⁺. © 1997 John Wiley & Sons, Inc.     

Neue,ungewöhnlich verlaufende Arylierungen der 1,5-Dihydroxy-4,8-diaminoanthrachinon-2,6-disulfonsäure mit Kresolen

A novel course of a phenylation reaction of 1,5-dihydroxy-4,8-diaminoanthraquin-one-2,6-disulfonic acid with cresols . The arylation of 1,5-dihydroxy-4,8-diaminoanthraquinone-2,6-disulfonic acid with m-cresol in conc. sulfuric acid gives in the presence of boric acid a mixture of monosulfonic acids which differ in the substitution of the m-cresol moiety. The main product ( 8 , 95%) is substituted at the p-position to the methyl group, the side product ( 12 , 5%) at the p-position to the OH group. The monosulfonic acid 8 , which could not be isolated is further sulfonated under the reaction conditions to the disulfonic acid 9 . In the case of o-cresol, the cresol moiety is substituted in the p-position ( 16 ) to OH group and in the case of p-cresol in the o-position ( 20 ) to OH group. The obtained monosulfonic acids 16 and 20 resp. are partially sulfonated further under the reaction conditions. The new structures are elucidated by ¹H- and ¹³C-NMR. spectroscopy and the pattern of arylation reaction with phenol is discussed.     

Structures of 1∶1 inclusion complexes of cholic acid with fluoroethanols; Conformational analysis of fluoroethanols in the host cavity

The crystal structures of the inclusion complexes of cholic acid (CA) with 2-fluoroethanol (MFEtOH), 2,2-difluoroethanol (DFEtOH) and 2,2,2-trifluoroethanol (TFEtOH) have been determined by X-ray crystallography, which demonstrates that the guest alcohols are accommodated inside the cavity provided by CA molecules in a similar manner to that for the ethanol molecule in the CA-ethanol inclusion complex. As distinct from the ethanol molecule, the methylene C atoms of the fluoroethanols are not disordered; instead, the substituted F atoms are statistically disordered. All the alcohols are hydrogen-bonded to the OH groups of CA. The X-ray study showed that 46% of MFEtOH adopt thetrans-trans conformer, which is different from the exclusively predominant conformer in the gas and liquid phases, i.e.,thegauche-trans conformer. The study also showed that the F atoms of DFEtOH are statistically disordered, suggesting the possibility that three conformers exist inside the cavity. Such disorder presumably occurs in order to fill the vacant space around the CH₂F and CHF₂ groups inside the cavity. By contrast, we could not observe any disorder of the F atoms of TFEtOH. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82176 (31 pages).