Octanol-Water Partition Coefficients of Simple Organic Compounds Cite as: Journal of Physical and Chemical Reference Data 18, 1111 (1989); https://doi.org/10.1063/1.555833 Submitted: 21 July 1988 . Published Online: 15 October 2009 James Sangster ARTICLES YOU MAY BE INTERESTED IN Evaluation of Data on Solubility of Simple Apolar Gases in Light and Heavy Water at High Temperature Journal of Physical and Chemical Reference Data 18, 1231 (1989); https:// doi.org/10.1063/1.555834 Direct calculation of 1-octanol–water partition coefficients from adaptive biasing force molecular dynamics simulations The Journal of Chemical Physics 137, 014502 (2012); https://doi.org/10.1063/1.4730040 A Critical Review of Aqueous Solubilities, Vapor Pressures, Henry’s Law Constants, and Octanol–Water Partition Coefficients of the Polychlorinated Biphenyls Journal of Physical and Chemical Reference Data 15, 911 (1986); https:// doi.org/10.1063/1.555755 Journal of Physical and Chemical Reference Data 18, 1111 (1989); https://doi.org/10.1063/1.555833 18, 1111 © 1989 American Institute of Physics for the National Institute of Standards and Technology. Octanol-Water Partition Coefficients of Simple Organic Compounds James Sangster Sangster Research Laboratories, Suite M-3, 1270 Sherbrooke St. West, Montreal, Quebec, Canada H3G 1H7 Received July 21, 1988; revised manuscript received January 30, 1989 Octanol-water partition coefficients (log P) for 611 simple organic compounds repre­ senting all principal classes have been retrieved from the literature. Available experimen­ tal details of measurement are documented from original articles. Pertinent thermody­ namic relations are presented, with a discussion of direct and indirect methods of measurement. Reported log P data for each compound have been evaluated according to stated criteria, and recommended values (with uncertainty) are given. Key words: octanol-water partition coefficient; organic compounds; hydrophobicity; hydrophilicity Contents List of tables ............................................................. 1111 2. General characteristics of some measurement List of symbols and abbreviations ............................ 1111 and estimation methods for P ........................... 1118 1. Introduction ........................................................ 1112 3. Partition coefficients of alkanes ......................... 1121 1.1. General ...................................................... .. 1112 4. Partition coefficients of alkenes and alkynes .... .. 1123 1.I.a. Definition ...................................... .. 1112 5. Partition coefficients of aromatics .................... .. 1125 Ll.b. Scope of this evaluation .................. 1112 6. Partition coefficients of cycloalkanes and cy- 1.1.c. Need for critical evaluation ............ 1113 cloalkenes .......................................................... 1141 1.2. Thermodynamics ....................................... 1113 7. Partition coefficients of mixed-type hydrocar- 1.2.a. General equilibrium relations ....... .. 1113 bons ................................................................... 1143 1.2.b. Temperature dependence ............... 1113 8. Partition coefficients of ethers .......................... .. 1144 1.2.c. Specific thermodynamic relations .. 1113 9. Partition coefficients of alcohols ....................... 1150 2. Methods of measurement .................................... 1116 10. Partition coefficients of aldehydes .................... .. 1163 2.1. Direct or "Experimental" methods ........... 1116 11. Partition coefficients of ketones ........................ 1165 2.1.a. Shake-flask ..................................... 1116 12. Partition coefficients of acids ............................ 1170 2. Lb. Generator column .......................... 1116 13. Partition coefficients of esters ............................ 1177 2.2. Indirect or "Calculation/correlation" 14. Partition coefficients ofhalogcnatcd compounds 1185 methods ...................................................... 1117 15. Partition coefficients of amines ......................... 1192 2.2.a. Methods widely used and/or having 16. Partition coefficients of nitriles ......................... 1216 some theoretical justification .......... 1117 17. Partition coefficients of nitro compounds ......... 1219 2.2.b. Other correlations ......................... .. 1117 18. Partition coefficients of amides ......................... 1221 3. Comparison of methods of measurement or esti- 19. Partition coefficients of sulphur compounds ..... 1225 mation ................................................................. 1117 20. Partition coefficients of other compounds ........ .. 1226 4. Retrieval of data........... .... .................................... 1117 5. Criteria for evaluation.......................................... 1118 6. Presentation of data in Tables 3-20..................... 1119 7. References ............................................................ 1227 List of Symbols and Abbreviations a = activity List of Tables AMB = ambient temperature AQ = octanol-saturated water phase 1. Temperature dependence of Log P of some com- AS = absorption spectrophotometry pounds at room temperature................ .............. 1113 B = organic base c = concentration Cp = heat capacity at constant pressure © 1989 by the U.s,. Secretary of Commerce on behalf of the United States. CR = chemical reaction This copyright is assigned to the American Institute of Physics and the D = direct method American Chemical Society. FL = fluorescence Reprints available from ACS; see Reprints Lists at back of issue G = Gibbs energy 0047-2689/89/031111-120/$12.00 1111 J. Phys. Chern. Ref. Data, Vol. 18, No.3, 1989 1112 JAMES SANGSTER GC = generator column x = mole fraction GLC = gas-liquid chromatography X = solute h = chromatographic peak height, Eq. (28) ? = doubtful Log P value; Code uncertain H = enthalpy HA = organic acid Greek HM = Henry's law constant 6. = difference in thermodynamic function (RP)-HPLC = (reverse-phase) high pressure liquid chromatography r = volume-fraction activity coefficient I = indirect method II- = chemical potential K = Kjeldahl method tp = volume fraction Ka = acid ionization constant , = solubility (mol L - I) 1 liquid = Superscripts m,n = correlation constants, Eq. (10) aq = octanol-saturated water phase NS = neutral salt solution . 0 = standard state ORG = water-saturated octanol phase oct = pure octanol phase p = pressure org = water-saturated octanol phase P = partition coefficient sat = phase saturated with solute Papp = apparent partition coefficient w = pure water phase RC radiochemical method = = Hansch & Leo "selected" Log P value s = solid * S ~ entropy SUblicdpllj SF = shake-flask method app = apparent (partition coefficient) T = temperature (kelvin) fus = fusion Temp. = temperature of log P measurement (OC) f = final TN = titration -initial V = volume (general) org = water-saturated octanol phase V = molar volume (L mol- 1) tr = transfer process W = octanol-saturated water solvent X = solute 1. Introduction acids, amines, and quaternary ammonium salts, which may also form dimers or ion-pairs. This is discussed further in this Introduction. 1.1. General In addition, the solvents represented in Eq. (1) are those mutually saturated with each other at the temperature of 1.1.a. Definition measurement. This is a natural consequence of the classical A pure substance may distribute itself between two par­ "shake-flask" or extraction method used in experimental tially miscible solvents in intimate contact, and the equilibri­ measurement ofP, and is to be taken into account for accura­ um ratio of solute concentrations in the two phases has come cy in measurement and thermodynamic interpretation. to be known as the distribution coefficient or partition coeffi­ Further, Pis preferably defined as the quantity which is cient,1 In preparative organic chemistry, the use of solvents independent of concentration, i.e., that value for which the of greatly differing polarity (e.g., hydrocarbon and water) solute obeys Henry's law in both solvents simultaneously. In facilitates the extraction and purification of desired prod­ practice, this means a P determined at high dilution, or ex­ ucts. In addition, the biological activity of simple organic trapolated to zero concentration. Since P as measured can 2 6 cornpound~ waq early found to correlate with their oil-water range over many orders of magnitude (10- to 10 ), it is partition coefficients.2 It became apparent that, for biologi­ usually expressed as its decadic logarithm, log P. cal purposes a partition coefficient based on long-chain ester or alcohol solvents was more appropriate. After some delib­ eration, l-octanol was chosen as the most useful lipophile 1.1.b. Scope of this evaluation solvent in these applications. Most correlation work has been done using the octanol-water pair, and this is the reason This work proposes to have retrieved and evaluated for its wide use and the existence of a great quantity of data most of the signifioant published experimentally determined on the subject. values oflog P of simple organic molecules. The word "sim­ The octanol-water partition coefficient of a substance X ple" is taken here to indicate molecules containing no or only at a given temperature is, by general consent, 1 represented by one polar functional group, i.e., a group having N,O,S P and defined by (for reasons explained later, the super­ and/or halogen atom. A few well-known exceptions