bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ring transformations of heterocyclic compounds with nucleophiles. Part XVI. Degenerate ring transformations of 1,3‐diethyl‐1,4(3,4)‐dihydro‐4‐oxopyrimidinium tetrafluoroborates with ammonia
Authors: Oostveen E. A. , van der Plas H. C. 
Published: September 2010

AbstractTreatment of 1,3‐diethyl‐1,4(3,4)‐dihydro‐4‐oxopyrimidinium tetrafluoroborate and its 2‐phenyl, 6‐phenyl, 6‐methyl and 6‐ethoxy derivatives with aqueous ammonia resulted in the formation of a mixture of open‐chain compounds i.e. N‐formyl(acetyl,benzoyl)‐N‐ethyl‐3‐(ethylamino)‐acrylamides and N‐ethyl‐3‐[formyl(acetyl,benzoyl)ethylamino]‐acrylamides. They are formed by cleavage of the pyrimidine ring between the N(1)‐C(2) and N(3)‐C(2) bond, respectively. In liquid ammonia the same ring cleavage generally occurs; however, in the case where a 6‐ethoxy group is present, recyclisation can take place, leading to 6‐(ethylamino)pyrimidine derivatives. This degenerate ring transformation has been observed also with the 2‐methyl and 2‐phenyl derivative of 1,3‐diethyl‐1,4(3,4)‐dihydro‐6‐ethoxy‐4‐oxopyrimidinium tetrafluoroborate. Evidence is presented by means of 1H‐NMR and 13C‐NMR spectroscopy that all these reactions are iniated by attack of NH3 at the C(2)‐position. Some of the above‐mentioned open‐chain compounds underwent a ring closure to the initially used 1,3‐diethyl‐1,4(3,4)‐dihydro‐4‐oxopyrimidinium tetrafluoroborates on treating them with hydrofluoroboric acid in absolute ethanol.
ESR investigation of the radical intermediates formed in the photoreduction of azo dyes
Authors: Heijkoop G. , van Beek H. C. A. 
Published: September 2010

AbstractESR‐spectra of hydrazyl and aminonaphthoxy radicals formed upon photoreduction of azo dyes have been measured. For the hydrazyl radicals the results obtained further confirm previous investigations of the mechanism of photoreduction of azo dyes. The direct identification in photo‐reduced dye solutions of aminonaphthoxy radicals, which are formed in the oxidation reduction equilibrium of aminonaphthols and iminoquinones provides strong evidence for previously proposed mechanisms for the disproportionation of hydrazyl radicals
Thermal addition of tosyl cyanide to norbornadiene. A Homo‐Diels‐Alder cycloaddition versus homo‐conjugate 1,4‐addition
Authors: Jagt J. C. , van Leusen A. M. 
Published: September 2010

AbstractTosyl cyanide reacts smoothly with norbornadiene to form a nortricyclene‐derived tetracyclic lactam (4) by a [2 + 2 + 2]‐cycloaddition (Homo‐Diels‐Alder reaction), and two other nortricyclene derivatives by homo‐conjugate 1,4‐addition reactions. The structure and stereochemistry of the reaction products 4, 5 and 6 are fully elucidated by 1H and 13C NMR spectroscopy.
Vinylcopper(I) compounds: Part III: Direct conversion of 1‐alkenylcuprates into stereospecifically substituted 1‐halogeno‐1‐alkenes
Authors: Westmijze H. , Meijer J. , Vermeer P. 
Published: September 2010

AbstractHalogenation of vinylcopper(I) compounds [RR′CCHCu(Br or R)]MgX, prepared stereospecifically bycis‐addition of [RCuBr]MgX or [R2Cu]MgX to 1‐alkynes R′‐C≡CH in tetrahydrofuran, with one of the halogenating reagentsN‐chlorosuccinimide,N‐bromosuccinimide, BrCN, ICN or I2, leads in high yields to the corresponding 1‐halogeno‐1‐alkenes RR′CCHX (X = Cl, Br or I). The introduction of the halogen atom occurs with retention of configuration (ciswith respect to R).
The crystal and molecular structures of 4,6‐diethoxy‐1‐ethylpyrimidinium tetrafluoroborate and 6‐ethoxy‐1,3‐diethyl‐1,4(3,4)‐dihydro‐4‐oxopyrimidinium tetrafluoroborate, two isomeric reaction products of 4,6‐diethoxypyrimidine with Meerwein reagent
Authors: Heijdenrijk D. , Stam C.H. , Oostveen E.A. , van der Plas H.C. 
Published: September 2010

AbstractThe crystal and molecular structures of two isomeric compounds, 4,6‐diethoxy‐1‐ethylpyrimidinium tetrafluoroborate and 6‐ethoxy‐1,3‐diethyl‐1,4(3,4)‐dihydro‐4‐oxopyrimidinium tetrafluoroborate, reaction products of 4,6‐diethoxypyrimidine with Meerwein reagent [O(C2H5)+3 BF−4], have been determined by means of X‐ray diffraction.4,6‐Diethoxy‐1‐ethylpyrimidinium tetrafluoroborate is monoclinic a = 10.794, b = 13.361, c = 10.892 Å, β = 112.6°, space group P21/n, four molecules per unit cell.6‐Ethoxy‐1,3‐diethyl‐1,4(3,4)‐dihydro‐4‐oxopyrimidinium tetrafluoroborate is monoclinic, a = 17.637, b = 14.054, c = 11.501 Å, β = 101.7°, space group C2/c, eight molecules per unit cell.In both structures the fluoroborate ions are disordered. The bond distances in the π‐electron systems are reasonably well described in terms of a small number of resonance structures.
Immobilized NADH models: (Preliminary communication)
Authors: Pandit U.K. , Gase R.A. , Cabré F. R. Mas , den Breejen‐Metz V. 
Published: September 2010

AbstractReduction of trifluoroacetophenone by solid‐supported NADH models has been demonstrated and shown to be dependent upon the length of the spacer unit between the polymer surface and the reagent.
Studies on polypeptides XXII: A synthetic hexapeptide as a standard substrate for Chymosin (Rennin)
Authors: Schattenkerk Cecile 
Published: September 2010

AbstractThe preparation of the hexapeptide Leu‐Ser‐Phe‐Nle‐Ala‐Ile‐OMe, using “solution synthesis” is described. The hexapeptide is an excellent standard substrate for chymosin.
The chemistry of small‐ring compounds. Part 39. Displacements in cyclopropyl chlorides activated by electron‐donating substituents
Authors: van der Vecht J. R. , Steinberg H. , de Boer Th. J. 
Published: September 2010

AbstractCyclopropyl chlorides with a methoxy‐ or a p‐tolyl group linked to the same carbon atom as halogen undergo substitutions in polar solvents with relatively little ring rupture, when the nucleophile is sufficiently reactive (e.g. methanol, N−3, Br−) to trap the intermediate α‐substituted cyclopropyl cations.Such substitution reactions are of the SN1 type and do not proceed via cyclopropene intermediates. With poor nucleophiles such as NO−3 in aqueous acetone, only polymeric ring‐opened products are formed.
Photolysis of some N‐cycloalkyl‐N‐halosulfonamides
Authors: Dekker E. E. J. , Engberts J. B. F. N. , de Boer Th. J. 
Published: September 2010

AbstractN‐Cycloalkyl‐N‐halo‐tosylamides 1a‐c and 2a‐b with three‐, four‐ and five‐membered cycloalkyl groups have been photolysed in methanol/dichloromethane at −80° and −10°. The resultant ω‐halo‐alkylidenesulfonamides or N‐cycloalkylsulfonamides are formed as outlined in Schemes 1 and 2. The influence of ring size on the tendency towards ring fission in intermediate amidyl radicals ‐ resulting from N‐Cl (N‐Br) homolysis ‐ is closely analogous to such tendencies found in corresponding N‐nitroso derivatives: dominant ring rupture in cyclopropyl and cyclobutyl derivatives, and no ring fission in cyclopentyl derivatives.Whatever the ring size, elimination of HCl or HBr with formation of a CN double bond does not take place in the photolysis of N‐halosulfonamides. This is in sharp contrast with the A'‐nitroso derivatives where exocyclic CN bond formation by HNO elimination of HNO is a common process for derivatives with a cyclobutyl or larger ring substituent.
Chemistry of peroxyacyl nitrates I. Thermal decomposition in cyclohexane solution; effect of added nitric oxide and of nitrogen dioxide
Authors: van Swieten A. P. , Louw R. , Arnoldy P. 
Published: September 2010

AbstractThe peroxyacyl nitrates 1b and 1c, in cyclohexane solution (0.01 − 0.1 M, 25‐60°C) decompose smoothly, displaying first‐order kinetics. Added nitrogen dioxide lowers the rate (approx. 3 x) but added nitric oxide results in a (7‐fold) rate enhancement, independent of the NO concentration. Under the latter circumstances the Arrhenius parameters for 1b are: log A/s−1 = 15.3, Ea = 26.7 kcal.mole−1.Products from 1b include CO2 (>85%), RNO2, RONO, ROH and corresponding derivatives from solvent cyclohexane. 1b does not produce caproic acid, but m‐chlorobenzoic acid together with chlorobenzene (RH), are prominent products from the thermolysis of 1c.These features are interpreted via a homolytic mechanism involving primary steps [1] and [2]. With added NO, step [1] is rate‐determining, whereas with added NO2 decomposition occurs via reaction [2].The relevance of radical pair (cage) processes is outlined.Attack on solvent occurs by transient free‐radical intermediates (e.g. R*, RO*) and by nitrogen dioxide.The effect of other additives (such as dihydroanthracene, resulting in RCO3H as isolable product) is in accord with this mechanism.Thermochemical‐kinetic features are discussed.
Metallation of 1,3‐dienyl ethers and 1,3‐dienyl sulfides in the 1‐position
Authors: Everhardus R. H. , Gräfing R. , Brandsma L. 
Published: September 2010

Abstract1,3‐Dienyl ethers and the corresponding sulfides (CH2CHCHCHXR; XO, S; Ralkyl, phenyl) are readily metallated at C‐1, usingn‐butyllithium and KO‐t‐Bu in tetrahydrofuran. 2H‐Thiopyran can be lithiated at the 6‐position withn‐butyllithium and tetramethylethylenediamine in tetrahydrofuran. The various metallated compounds react smoothly with methyl iodide, methyl thiocyanate and acetaldehyde to give the expected derivatives. At about −20° a more than 95 % transformation of the metallated compound fromcisCH2CHCHCHStBu into thetrans‐isomer occurs; with smaller R groups (isopropyl or ethyl) a less complete inversion is observed.
Interaction energy calculations in zeolites. Part I. The electrostatic field in Y and A zeolites
Authors: Michelena Joseba A. , Vansant Etienne F. , de Bièvre Paul 
Published: September 2010

AbstractTo evaluate the interaction energy of molecules adsorbed in the Y and A zeolites, the electrostatic field has been calculated in the large cavities. The zeolites have been considered as crystals consisting of point charges, with the positive charges statistically localized at all cationic sites and the negative charges distributed equally among the lattice oxygens. In general, for both zeolites the electrostatic fields are mainly determined by the exchangeable cations. Furthermore, the calculations have shown that, in contrast with the Y zeolite, the field obtained in a large cavity of the A zeolite differs considerably when it is calculated with or without taking into account the ions belonging to the surrounding large cavities.
Interaction energy calculations in zeolites. Part II. The interaction energy of Ar, CO and CO2 molecules adsorbed in the zeolites NaY and CaY
Authors: Michelena Joseba A. , Vansant Etienne F. , de Bièvre Paul 
Published: September 2010

AbstractThe interaction energies of Ar, CO and CO2 molecules adsorbed in the large cavities of the zeolites NaY and CaY have been determined from the calculation of the dispersion, polarization, field‐dipole, field gradient‐quadrupole and repulsion components for different positions of the molecules. We have illustrated theoretically the non‐cation specificity of adsorbed Ar molecules and the cation‐specific behaviour of the CO molecules in Y‐type zeolites. A comparison between calculated interaction energies and the experimental isosteric heats has been carried out. A possible mechanism for the CO2 chemisorption has been suggested.
Cannabis XVIII: Isolation and synthesis of olivetol derivatives formed in the pyrolysis of cannabidiol
Authors: Luteyn J. M. , Spronck H. J. W. , Salemink C. A. 
Published: September 2010

AbstractPyrolysis of cannabidiol results in the formation of several new cannabinoids and cracking products. In an earlier paper several structures were proposed for the cracking products based on GCMS measurements. In this paper the isolation and synthesis of the majority of these cracking products ‐ which are in general C(2)‐substituted olivetol derivatives ‐ is described. 2,6‐Dimethoxy‐4‐pentylphenyl‐lithium and the cuprates derived therefrom proved to be very promising intermediates for the synthesis of olivetol derivatives specifically substituted at C(2). The versatility of these reagents is illustrated by several examples.
Chemistry of the SO bond. Part 7. The crystal structure of 1,1,3‐trimethyltrimethylene sulfite: A sulfite with an equatorial SO
Authors: Petit G. , Lenstra A. T. H. , van De Mieroop W. , Geise H. J. , Hellier Desmond G. 
Published: September 2010

Abstract1,1,3‐Trimethyltrimethylene sulfite crystallizes in the monoclinic space group P21/c with a = 7.419 Å, b = 8.640 Å, c = 12.708 Å, β = 95.58° and Z = 4 at −90°C. The structure was solved using Patterson and difference Fourier techniques and refined by block‐diagonal least‐squares to a final R value of 6.9%.The double bonded oxygen is found in the unusual equatorial position. The conformation features are compared with similar compounds having the S=O group in the common axial position.
Aromatic lead(IV) compounds IX: 13C‐FT‐NMR spectroscopy of compounds of the type Ar4Pb
Authors: de Vos D. , Wolters J. 
Published: September 2010

Abstract13C chemical shifts and 207Pb‐13C coupling constants are reported for tetraaryllead compounds. These data demonstrate a strong dependence upon the nature and position of the substituent in the aromatic nucleus.
Cannabis XIX. Oxygenated 1,2‐Diphenylethanes from Marihuana
Authors: Kettenes‐van den Bosch J. J. , Salemink C. A. 
Published: September 2010

AbstractThe presence of several hydroxy‐ and methoxy‐substituted 1,2‐diphenylethanes in Mexican marihuana has been established. The structure of three of these compounds has been elucidated. The products may have physiological activity. Their role as precursors for cannabispiro compounds is discussed.
On the reversibility of the formation of peroxyl radicals from oxygen and alkyl radicals
Authors: Bolsman T. A. B. M. , Brouwer D. M. 
Published: September 2010

AbstractGeneration of the 16O‐tert‐butylperoxyl radical at 130°C in the presence of 18O2 does not result in the incorporation of 18O into the decomposition products, which confirms that the dissociation of the peroxyl radical into molecular oxygen and an alkyl radical is very slow compared with the propagation step in the autoxidation of isoalkanes.
The role of tetraalkylammonium salts in the electro‐reduction of ketones. I. Competitive adsorption in an aqueous medium
Authors: van Tilborg W. J. M. , Dekker L. J. G. , Smit C. J. 
Published: September 2010

AbstractAryl alkyl ketones and tetraalkylammonium ions compete for adsorption in the region where the adsorption voltage ranges of the respective compounds overlap. A study has been made of the effects of changes in structure of the tetraalkylammonium salts as well as of the ketones, of the nature of the anion and of the polarity of the medium on this competitive adsorption. It is concluded that in the presence of tetraalkylammonium ions the reduction of a corbonyl compound occurs on top of an adsorbate layer of such ammonium ions. Consequences of the results reported with respect to the mechanism of asymmetric induction in carbonyl reduction and of the mechanism of electropinacolization are discussed.
X‐Ray structure of the inherently dissymmetric olefin D,L‐trans‐1,2,3,4,1′,2′,3′,4′‐octahydro‐4,4′‐biphenanthrylidene
Authors: Feringa Ben , Wynberg Hans , Duisenberg Albert J. M. , Spek Anthony L. 
Published: September 2010

AbstractX‐Ray data for inherently dissymmetric D,L‐trans‐1,2,3,4,1′,2′,3′,4′‐octahydro‐4,4′‐biphenanthrylidene are presented; the molecular symmetry is C2. Small double‐bond torsion and twist boat cyclohexene conformations have been established.
The molecular structure of 3β‐acetoxy‐2β‐hydroxy‐thujopsane, C17H28O3
Authors: Olthof G. J. , Overbeek A. R. , Putten N. V. D. , Schenk H. 
Published: September 2010

AbstractThe sesquiterpenoid 3β‐acetoxy‐2β‐hydroxy‐thujopsane forms orthorhombic crystals of space group P212121 with cell dimensions a = 7.547, b = 14.167, c = 14.783 Å and Z = 4. The cyclohexane ring carrying the cyclopropane ring is approximately in a half chair conformation and the other ring is a slightly deformed chair. Two bonds of the cyclopropane ring are shortened (to 1.490 and 1.492 Å) and one is lengthened (to 1.534 Å), an uncommon phenomenon, which is assumed to be correlated with the position of the hydroxyl‐oxygen atom with respect to the cyclopropane ring.
Propellanes. XLVII. The reaction of 11,13‐dioxo‐12‐methyl‐12‐aza[4.4.3] propella‐2,4,7,9‐tetraene and ‐2,4‐diene with singlet oxygen
Authors: Landheer Iman , Ginsburg David 
Published: September 2010

AbstractSinglet oxygen attacks 3 from the direction syn to the hetero‐ring.
Photochemistry of vicinal diaryl tetraketones
Authors: Rubin Mordecai B. , Krochmal Emil C. , Kaftory Menahem 
Published: September 2010

AbstractIrradiation of vicinal diaryl tetraketones in a variety of solvents yields tricyclic products 2 in high yields. The structure of the product from di‐p‐bromophenyl tetraketone was determined by X‐ray crystallographic analysis.
1H‐CIDNP effects in the reaction of N‐hydroxyureas with tert‐butylsulfinyl chloride in the presence of a tertiary amine
Authors: Bleeker Ido P. , Engberts Jan B. F. N. 
Published: September 2010

Abstracttert‐Butylsulfinyl chloride (1) reacts smoothly with N′‐(di)methyl‐ and N′‐(di)phenyl‐N‐hydroxyurea (2) in acetone at room temperature, in the presence of two equivalents of pyridine. An intermediate O‐tert‐butylsulfinyl‐N‐hydroxyurea (3) is postulated, which rearranges via a radical cage mechanism to give the corresponding N‐tert‐butylsulfonylurea as the recombination product. Several escape products are also isolated. This thermally induced rearrangement involves homolytic cleavage of the N‐O bond in 3. The process is accompanied by pronounced 1H‐CIDNP effects, which may be interpreted using Kaptein's rule. The fate of the N′‐(di)substituted carbamoylaminyl radicals, formed initially within the radical pair, is discussed. N′,N′‐diphenyl‐N‐hydroxyurea shows deviant behaviour and the major reaction product is in this case diphenylamine.
Geometrical isomers of thione S‐imides
Authors: Tangerman A. , Zwanenburg B. 
Published: September 2010

AbstractReaction of highly substituted dithiobenzoates 1 (a‐e) with chloramine‐T in methanol at 20°C gives, in high yields, thione S‐imides 2 (a‐e) to which the E‐geometry was assigned. Heating of these compounds in methanol for 1 hr causes thermodynamic isomerization to the Z‐isomers 3 (a‐e). Similarly, 2,4,6‐trimethyl‐thiobenzophenone gives the corresponding E‐ and Z‐S‐tosylimides 6 and 7. Irradiation of thione S‐imides 2, 3, 6 and 7 leads to extrusion of sulfur yielding N‐tosylimines 4 and 8. The geometrical configurations were based on ASIS experiments. From the 1H‐NMR spectra of 2 and 3 the preferred conformation of the thione S‐imides have been deduced (S‐trans conformation for the E‐isomer 2 and a folded S‐cis conformation for the Z‐isomer 3). It will be shown that in order to obtain stable thione S‐tosylimides from dithiobenzoates and thiobenzophenones, steric hindrance in the direct environment of the thiono function is a prerequisite.
Photochemical cycloaddition of an aromatic ketone to a 1‐alkynyl ether. Kinetics and mechanism
Authors: Polman H. , Baaij J.P.B. , Bos H.J.T. 
Published: September 2010

AbstractIn this paper kinetics and mechanism of the photoaddition of 10,11‐dihydro‐5H‐dibenzo‐[a,d]cyclohepten‐5‐one (dibenzosuberone, 4) to 1‐methoxy‐1‐propyne (5) with the formation of the unsaturated ester 8, are studied. In benzene at 25.0°C a limiting quantum yield Φ = 0.04 was found. The rate constant k2 of the addition of triplet ketone 4 to ground state 5 amounted to 1.9 · 1077 l.mol−1,s−1. The unexpected regiospecificity is not caused by attack of triplet alkyne on ground state ketone. The low quantum yield is mainly caused by the high revertibility of the addition reaction. The intermediacy of a triplet exciplex is discussed.
A study on the regio‐ and stereo‐chemistry of organocuprate additions to 1,2,3‐butatrienes
Authors: Kleijn H. , Westmijze H. , Schaap A. , Bos H.J.T. , Vermeer P. 
Published: September 2010

AbstractA number of 1,2,3‐butatrienes, R1R2CCCCH2 (1; R1 = H, Me or t‐Bu; R2 = H or Me) have been allowed to react with organocuprates of the type R32CuMgX·LiBr (2; R3 = alkyl or Ph) in tetrahydrofuran. In most cases the (E)‐1,3‐dienes R1R2CCHCR3CH2 (3) are formed mainly but sometimes substantial amounts of the compounds R1R2CCCHCH2R3 (4), R1R2CHC≡CCH2R3 (5) and R1R2CCR3‐CHCH2 (6) have also been isolated. A mechanism for the addition reaction is proposed.
Biomimetic total synthesis of steroids IV. Stereoselective synthesis of 15α‐methyl‐19‐norsteroids
Authors: Groen M.B. , Zeelen F.J. 
Published: September 2010

AbstractThe cationic cyclization of 2‐[6‐(m‐methoxyphenyl)‐(E)‐3‐hexenyl]‐3,5‐dimethyl‐2‐cyclopentenol (3) was investigated. Exclusive formation of 1‐ and 3‐methoxy‐15α,17‐dimethyl‐1,3,5(10), 13(17)‐gonatetraene (4 and 5) was observed, indicating complete stereoselectivity in the cyclization process. Compound 4 was converted into dl‐15α‐methylestrone methyl ether (7) and hence into dl‐15α‐methylestradiol 3‐methyl ether (8). The structure of these hitherto unknown compounds was proved by independent syntheses.
Chiral organolead compounds. Part 1. [2‐(Dimethylaminomethyl)phenyl](4‐methoxyphenyl)(4‐methylphenyl) lead iodide
Authors: van der Kooi H. O. , Wolters J. , van der Gen A. 
Published: September 2010

AbstractA synthetic route to a chiral triorganolead halide of the type ArAr′Ar″PbX is described. A prochiral diorganolead diacetate was prepared by plumbylation and subsequent transmetallation. After substitution of the two acetate groups by iodide, the prochiral intermediate was selectively arylated with ortho‐lithiated N,N‐dimethylbenzylamine in which a potential built‐in ligand is present. The PMR spectrum of the resulting chiral triorganolead iodide showed no diastereotopic effects of the N(CH3)2 and of the benzylic protons. Data of the crystal and molecular structures of this novel chiral lead compound obtained from a single‐crystal X‐ray diffraction study are reported. The crystal structure is isomorphous with that of [2‐(dimethylaminomethyl)phenyl]diphenyltin bromide.
The effect of γ‐substituents on the vicinal carbon‐proton spin‐spin coupling constants in aliphatic compounds
Authors: Spoormaker Tom , Zwikker Jan W. , de Bie Marius J. A. 
Published: September 2010

AbstractThe increments in 3J(CH) for substituents attached to Cγ in the 13Cα‐Cβ‐Cγ‐1H coupling pathway, with respect to 3J(CH) in propane are calculated for equal Cβ‐Cγ rotamer population from 3J(CH) observed in the corresponding neopentyl compounds. From these increments the preferred conformation of the n‐propyl compounds can be deduced.
Réactions d'oximation de cétones III. Effets de structure dans la réaction d'addition neutre et acido‐catalysée de l'hydroxylamine
Authors: Lamaty G. , Petitjean A. , Roque J. P. , Natat A. 
Published: September 2010

AbstractRate constants for addition of hydroxylamine to a series of twenty‐four ketones have been measured, in water at 25,00 ± 0,02°C, for both acid‐catalyzed (k) and pH‐independent (ko) pathways. Structural effects seem to be operating in the same manner on ko and k values, except in a few cases. Results are consistent with a “reactant‐like” transition state.
Zinc(II), cadmium(II) and mercury(II) complexes with 2,5‐diphenyloxazole
Authors: Biddau M. , Massacesi M. , Pinna R. , Ponticelli G. 
Published: September 2010

AbstractA number of compounds of general formula M(PPO)nX2 are described, the metal ion being Zn(II), Cd(II) and Hg(II) and the anions Cl−, Br−, I−, NO3−, ClO4− and NCS−; PPO stands for 2,5‐diphenyloxazole and n = 1, 2, 4.The complexes are prepared by reaction of the corresponding metal salts with the molten ligand in the required stoicheiometrical ratio and are characterized by chemical analyses and physical measurements.Their stereochemistry has been assigned on the basis of IR, far IR spectroscopy and molar conductivity values. The ligand PPO is shown to co‐ordinate with metal ions via the lone‐pair electrons of the nitrogen atom. All the complexes have generally a distorted tetrahedral stereochemistry.