The 4-phosphacyclohexanones, 2,2,6,6-tetramethyl-1-phenyl-4-phosphorinanone (La), 1,2,6-triphenyl-4-phosphorinanone ((Ph)Lb), 1-cyclohexyl-2,6-diphenyl-4-phosphorinanone ((Cy)Lb) and 1-tert-butyl-2,6-diphenyl-4-phosphorinanone ((Bu)Lb) have been made by modifications of literature methods. Phosphines (R)Lb are each formed as mixtures of meso- and rac-diastereoisomers. Isomerically pure rac-(Ph)Lb, rac-(Cy)Lb and meso-(Bu)Lb can be isolated by recrystallisation from MeCN. Heating mixtures of isomers of (R)Lb with TsOH leads to isomerisations to give predominantly the meso-(R)Lb. The complex trans-[PdCl2(La)2] (1) is readily made from [PdCl2(NCPh)2] but the analogous platinum complex 2 has not been detected and instead, cyclometallation at the 3-position (alpha to the ketone) in the phosphacycle occurs to give trans-[PtCl(La)(La-3H)] (3) (where La-3H = La deprotonated at the 3-position) featuring a [3.1.1]metallabicycle as confirmed by X-ray crystallography. The analogous palladabicycle 4 has been detected upon treatment of 1 with Et3N in refluxing toluene. The type of complex formed by (R)Lb depends on which diastereoisomer (meso or rac) is involved. rac-(Ph)Lb (a mixture of R,R- and S,S-enantiomers, labelled alpha and beta) forms trans-[MCl2(rac-(Ph)Lb)2], M = Pd (5) or Pt (6), as mixtures of diastereoisomers (alphaalpha/betabeta and alphabeta forms). The structure of alphaalpha-6 has been determined by X-ray crystallography. Ligand competition experiments monitored by 31P NMR showed that Pd(II) and Pt(II) have a significant preference to bind rac-(Ph)Lb over meso-(Ph)Lb. meso-(Bu)Lb reacts with [PtCl2(NCBu(t))2] under ambient conditions to give the binuclear complex [Pt2Cl2(meso-(Bu)Lb-2'H)2] (7) where orthometallation has occurred on one of the exocyclic phenyl substituents as confirmed by X-ray crystallography. rac-(Bu)Lb reacts with [PtCl2(NCBu(t))2] to give a mononuclear cyclometallated species assigned the structure trans-[PtCl(rac-(Bu)Lb-2'H)((Bu)Lb)] (8) on the basis of its 31P NMR spectrum. rac-(Cy)Lb reacts with [PtCl2(NCBu(t))2] in refluxing toluene to give trans-[PtCl2(rac-(Cy)Lb)2] (9) and the crystal structure of alphabeta-9 has been determined.

here; the transfer process can involve either partitioning or adsorption, the “solvent” being a surface in the latter case.) The principal solvation process in chromatographic separation is the creation of an acceptor cavity in (or on) the stationary‘phase and the destruction of the donor cavity in the mobile phase. Thus binding processes and chromatographic retention processes are quite different: the former requires only the change of cavity size in a single solvent; the latter requires creation of a cavity in one solvent and the destruction of a cavity in another solvent. The solvophobic theory is based on the premise that the only cavity which is relevant to retention is that in the mobile-phase solvent; it neglects the acceptor cavity in the stationary phase. Consequently, it predicts that retention should depend only on the surface tension of the mobile-phase solvent and not on the surface tension or other physical properties of the grafted stationary phase. In a partitioning theory such as the present one, cavities are described through the binary interaction constants, x; their differences account for the driving force for retention. The solvophobic theory therefore errs in important respects. For example: (i) it does not rationalize the general observationws that In k’should be a simple function of a relevant partition coefficient, and (ii) it specifies that retention should be independent of the nature of the grafted chain phase. There is much evidence that retention does depend on the grafted chain phase, some of which unambiguously cannot be interpreted in terms of effects of the phase ratio.35.58-61

Ostwald solubility coefficients, as log L, for solutes in water and ethanol have been combined to give log PEtOH for partition between the two pure solvents. Sixty-four such values have been correlated through our solvation equation, the coefficients of which lead to the conclusion that ethanol and water solvents are equally strong hydrogen-bond bases, but that ethanol is much weaker as a hydrogen-bond acid. A slightly different solvation equation has been used to correlate 68 values of log LEtOH; the coefficients in this equation yield the same conclusions as to the hydrogen-bond acidity and basicity of bulk ethanol. In addition, an analysis of the various terms in the log LEtOH correlation equation allows the elucidation of the various chemical factors that govern the solubility of gaseous solutes in ethanol solvent at 298 K.Key words: solubility, partition, hydrogen-bonding, ethanol, water.

The new solvation equation: log L = c + rR2 + s-pi-2H + alpha-alpha-2H + b-beta-2H + l log L16 has been applied to the solubility of 43 gaseous probes on each of nine hydrocarbon polymers using the data of Munk et al.. In this equation, L is the gas-liquid partition coefficient of a series of probes on a given polymer, and the explanatory variables are solute properties as follows: R2 is an excess molar refraction, pi-2H is the probe dipolarity-polarizability, alpha-2H and beta-2H are the probe hydrogen-bond acidity and basicity, and L16 is the gas-liquid partition coefficient of the probe on hexadecane at 25-degrees-C. Each of the nine equations, one for each polymer, had correlation coefficients of around 0.999 and standard derivations of around 0.025 log units. The solubility of the gaseous probes, as log L values, as well as the polymer-probe interaction parameter-chi calculated by Munk, have been analysed in terms of particular polymer-probe interactions.

The general solvation equation log K = c + rR2 + sπ2H + aα2H + bβ2H + l log L16 has been used to characterise 24 gas-liquid chromatographic stationary phases for which Poole and co-workers have determined log K values for a series of solutes at 121.4°C. The explanatory variables are R2, asolute excess molar refraction, π2H, the solute dipolarity, α2H and β2H, the solute hydrogen-bond acidity and basicity, and log L16, where L16 is the solute gas-liquid partition coefficient on hexadecane at 25°C. It is shown that the bβ2H term is not significant for any phase, and that the molten salts are all strongly dipolar and basic, with large s and a constants. A term-by-term analysis of the solvation equation yields a quantitative measure of the contribution to log K of various solute-stationary phase interactions, and leads to an understanding of how these interactions affect solute retention. The use of the characteristic constants c, r, s, a, b and l in the selection of stationary phases for particular separations is described.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The general salvation equation, log VG0 (or log L) = c + rR2 + sπ2H + aα2H + bβ2H + l log L16 has been used to set up a new π2H parameter of solute dipolarity-polarisability, mainly through the extensive data of McReynolds and Patte et al. Values of π2H are tabulated for several hundred solutes, and two simple rules have been formulated to enable π2H to be estimated for many types of aliphatic functionally substituted compounds. A coherent set of effective solvation parameters, Σπ2H, Σα2H, Σβ2H, and also R2 and log L16, allows the application of the general solvation equation to the characterisation of any gas-liquid chromatographic stationary phase.

The following equation has been applied to all the phases in the McReynolds 77-stationary phase set. In this equation, V0G is the specific retention volume for a series of solutes on a given stationary phase, and the explanatory variables are R2 a modified solute molar refraction, π*2 the solute dipolarity, αH2 the solute hydrogen-bond acidity, βH2 the solute hydrogen-bond basicity, and log L16 where L16 is the solute Ostwald absorption coefficient on hexadecane at 25°c. The constants in the equation are obtained by multiple linear regression analysis, using about 150 data points in eacy regression, and values of r, s, a, b and l are regarded as characteristic constants of the phases that serve to classify the 77-phase set. It is shown that the classification of the phases into clusters is in accord with chemical principles, and is in excellent agreement with previous work using hierarchical clustering, minimum spanning tree techniques, and pattern cognition methods. The above equation allows the factors that lead to gas-liquid chromatographic separations to be identified, and provides quantitative information on the various solute-solvent interactions that give rise to these factors.

Equations previously used for the characterisation of GLC stationary phases have been found to be equally suitable for the characterisation of common solvents. Thus equation (a) has been applied to solubility data for series of solutes on N-formylmorpholine (NFM), N-methylpyrrolidinone (NMP), N,N-dimethylformamide (DMF), and N,N-dimethylace amide (DMA).SP =c+r·R2+s·π2*+a·α2H+b·β2H+I· log L16(a)In equation (a), SP can be log V°G or log L for a series of solutes on a given solvent where V°G is the specific retention volume and L is the Ostwald solubility coefficient. The solte parameters are R2, a polarisability parameter; π2*, the solute dipolarity; α2H, the solute hydrogen-bond acidity; β2H, the solute hydrogen-bond basicity; and log L16 where L16 is the solute Ostwald solubility coefficient on n-hexadecane at 298 K.It is shown that at 298 K all four amides have about the same dipolarity, as judged by the s-constant, and have nearly the same hydrogen-bond basicity, as judged by the a·α2H term: all have zero hydrogen-bond acidity so that b= 0 in equation (a). Comparison can be made between results for NFM and NMP at 393 K and results for some GLC stationary phases. The two amides are less dipolar than tricyano(ethoxy) propane and diethyleneglycol succinate, about the same as Zonyl E-7®and Carbowax®, and more dipolar than poly(phenyl ether). The amides, however, have rather more hydrogen-bond basicity than any of the above five GLC phases. It is suggeted that equation (a) can be used as the basis of method for characterising condensed phases, such that common solvents as well as GLC stationary phases can be included within the scope of the method.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHydrogen-bonding. Part 11. A quantitative evaluation of the hydrogen-bond acidity of imides as solutesMichael H. Abraham, Priscilla L. Grellier, David V. Prior, Jeffrey J. Morris, Peter J. Taylor, and Ruth M. DohertyCite this: J. Org. Chem. 1990, 55, 7, 2227–2229Publication Date (Print):March 1, 1990Publication History Published online1 May 2002Published inissue 1 March 1990https://pubs.acs.org/doi/10.1021/jo00294a045https://doi.org/10.1021/jo00294a045research-articleACS PublicationsRequest reuse permissionsArticle Views119Altmetric-Citations9LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

A number of equations for the correlation of retention data for a series of solutes on a given stationary phase (or solvent) have been investigated with the aim of characterising stationary phases. The two most successful equations are, SP =c+dδ2+sπ2*+aα2H+bβ2H+I log L16(a), SP =c+rR2+sπ2*+aα2H+bβ2H+I log L16(b) In the present case the dependent variable SP is log L– log LDecane and the explanatory variables are solute parameters as follows: δ2 is an empirical polarisability correction term, R2 is a polarisability parameter that reflects the ability of a solute to interact with a solvent through π and n electron pairs, α2H is the solute hydrogen–bond acidity, β2H is the solute hydrogen–bond basicity, π2* is the solute dipolarity/polarisability, and L16 is the Ostwald solubility coefficient of the solute on n-hexadecane at 298 K. The constants c, r, s, a, b, and l in the more useful equation (b) are found by the method of multiple linear regression analysis, and serve to characterise a solvent phase in terms of specific solute/solvent interactions. Application of equation (b) to the five stationary phases examined by Laffort et al. shows that the magnitude of these constants is in accord with general chemical principles, and that the present procedure constitutes a new, general method for the characterisation of gas chromatographic stationary phases.

AbstractUsing the solvatochromic indicator method, a scale of solvent hydrogen‐bond basicity, β1 (General), has been set up using a series of double regression equations, for 11 aniline‐type indicators. A similar solvent scale, β1 (Special), has been constructed by the homomorphic comparison method using only results by Laurence et al. on the indicators 4‐nitroaniline and 4‐nitro‐N,N‐dimethylaniline. Results are available from our previous work on a general solute scale, β, and we have also obtained a special solute scale, β2 (pKHB) from available log K values for hydrogen‐bond complexation of bases with 4‐fluorophenol in CCl4. However, the two solute β2 scales are virtually identical.It is shown that there is a general connection between β1(General) and β, with r = 0·9775 and s.d. = 0·05 for 32 compounds, and between β1(Special) and β, with r = 0·9776 and s.d. = 0·06 for the same 32 compounds. The latter correlation over 60 compounds yields r = 0·9684 and s.d. = 0·07. However, there are so many compounds in these regressions for which the differences in the solvent and solute β values are larger than the total expected error of 0·07 units that the use of β1 to predict β2 or vice versa is a very hazardous procedure. About 70 new β1 values obtained by the double regression method are also reported.

Energies delivered at 7 volumes expansion in the cylinder test are well correlated for 16 typical and atypical explosives. The criterion for a typical explosive is that it have approximately 0.40 mole fraction of water vapor in the detonation products. The correlation equation is (V20)2 = 0.200ϕp01.50[1.104 − 0.265 MF(H2O)], with ϕ = NM12Q12 where V20 is the cylinder wall velocity in mmμs at 20 mm expansion in the 1-in. cylinder test, ϱ0 is the loading density, N is the number of moles of gaseous detonation products per gram of explosive (calculated by the H2OCO2 arbitrary), M is the average molecular weight of the gases, Q is the heat of detonation in cal/g, and MF(H2O) is the mole fraction of water vapor in the detonation products. For reasons that are not now known, the insensitive explosives TATB and nitroguanidine underperform by about 15% relative to the above equation.

Cylinder test energies of nonideal explosives are calculated on the basis of the following two assumptions: (a) that the detonation products of the overbalanced and underbalanced explosives have equilibrated completely to form the free energy-minimized detonation product composition at 7 volumes expansion; and (b) that each component has gone to its own detonation products, with no mixing or equilibration of the detonation species. From these calculations and the experimental cylinder test energy, the extent of interreaction is estimated. For the most efficient of the nonideal explosives tested, interreaction efficiencies approach 70%.

log k′ values on a C18 stationary phase with 90/10, 75/25, 60/40, 45/55 and 30/70 methanol–water mobile phases are correlated in terms of the generalized linear solvation energy relationship, log k′= XYZo+mVI/100 +sπ*+bβm+aαm where VI is the intrinsic (van der Waals) molar volume, and π*, βm, and αm are the solvatochromic parameters that measure solute dipolarity–polarizability, hydrogen-bond acceptor basicity, and hydrogen-bond donor acidity. The correlation equations are combined with the corresponding equation for octanol–water partition coefficients to generate new equations that demonstrate the exact relationships between the various log k's and log Kow.

ChemInformVolume 19, Issue 40 Physical Organic Chemistry ChemInform Abstract: Linear Solvation Energy Relationships. Part 39. A Multiple Substituent Parameter Equation for β-Values (Hydrogen-Bond Acceptor Basicities) of XYZP=O Compounds. R. W. TAFT, R. W. TAFT Dep. Chem., Univ. Calif., Irvine, CA 92717, USASearch for more papers by this authorW. J. SHUELY, W. J. SHUELY Dep. Chem., Univ. Calif., Irvine, CA 92717, USASearch for more papers by this authorR. M. DOHERTY, R. M. DOHERTY Dep. Chem., Univ. Calif., Irvine, CA 92717, USASearch for more papers by this authorM. J. KAMLET, M. J. KAMLET Dep. Chem., Univ. Calif., Irvine, CA 92717, USASearch for more papers by this author R. W. TAFT, R. W. TAFT Dep. Chem., Univ. Calif., Irvine, CA 92717, USASearch for more papers by this authorW. J. SHUELY, W. J. SHUELY Dep. Chem., Univ. Calif., Irvine, CA 92717, USASearch for more papers by this authorR. M. DOHERTY, R. M. DOHERTY Dep. Chem., Univ. Calif., Irvine, CA 92717, USASearch for more papers by this authorM. J. KAMLET, M. J. KAMLET Dep. Chem., Univ. Calif., Irvine, CA 92717, USASearch for more papers by this author First published: October 4, 1988 https://doi.org/10.1002/chin.198840036AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume19, Issue40October 4, 1988 RelatedInformation

The retention of 32 monocyclic aromatic compounds and 14 polynuclear aromatic hydrocarbons (PAHs) has been studied on four different bonded phases in each of two mobile phases. An additional data set of 21 monocyclic aromatics judiciously chosen for their well-established solvatochromic parameters, 12 PAHs and 12 polychlorinated biphenyls (containing up to 10 chlorines), were studied on a single column. The results indicate that despite the accuracy of the solvatochromic linear solvation energy method for predicting and correlating the octanol/water partition coefficients and water solubilities of these environmentally important materials, the methodology is limited to only certain types of bonded phases. As a corollary to this observation, we caution others that the common practice of estimating log Kow (Kow=octanol-water partition coefficient) based on measurement of the reversed-phase capacity factors should be limited to specific types of columns.

AbstractPhysical Organic Chemistry Interface.