Temperature Dependent Solubility of C 60. Speaker: Chun I Wang ( 王俊壹 ) & 11.03

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1 Temperature Dependent Solubility of C 60 Speaker: Chun I Wang ( 王俊壹 ) & 11.03

2 Fullerene (C 60 ) : Predicted the existence of C 60

3 Fullerene (C 60 ) 1985: Successful synthesis High atomistic surface density Poor solubility (hydrophobic and lyophobic ) ~1 nm cis-bicyclooctane Adamantane Fullerene

4 Solubility [mole fraction] Fullerene (C 60 ) 1993: Anomalous solubility of C 60 Temperature [K] Temperature dependent solubility of C 60 in hexane (+),toluene ( ), and CS 2 ( ) R. S. Ruoff et al., Nature 1993, 362, 140. Phase transition of C 60 Cluster formation Fullerene solvate

5 Solubility [mole fraction] Phase Transition vs. Temperature Dependent Solubility T max Phase transition In crystalline Simple cubic FCC Endothermic Temperature [K] Exothermic Temperature dependent solubility of C 60 in hexane (+),toluene ( ), and CS 2 ( ) R. S. Ruoff et al., Nature 1993, 362, H A In solution state Assume H A >H B >H s 260 K H s H B 280 K Thermodynamics model S H R RT SBS HBS x( T ) exp( ) for T T R RT AS AS x( T ) exp( ) for T Tmax max

6 Cluster Formation vs. Temperature Dependent Solubility Droplet model Assumption: Spherical cluster (C 60 ) n Contains a large number of molecules (n>>1) Transition from solid to solution doesn t change a molecule s individuality. 23 Bn Afcc H T S Tc T x x0 n exp( ) dn 1 T Interactions for solvent molecules placed on cluster s surface Interactions of a C 60 within a cluster Contribution of phase transition Temperature dependent solubility of C 60 in hexane (+),toluene ( ), and CS 2 (*) A. V. Eletskii et al., J. Phy. Chem. 1994, 98, 6665.

7 Cluster Formation vs. Temperature Dependent Solubility Droplet model 23 Bn Afcc H T S Tc T x x0 n exp( ) dn 1 T Interactions for solvent molecules placed on cluster s surface Interactions of a C 60 within a cluster Contribution of phase transition Inference: The decrease of solubility on warming is caused by the thermal dissociation of clusters. The characteristic size (n*) of clusters increase from n*(190 K)=3 to the value n*(260 K)=11, which remain the same up to 380 K. Temperature dependent solubility of C 60 in hexane (+),toluene ( ), and CS 2 (*) A. V. Eletskii et al., J. Phy. Chem. 1994, 98, 6665.

8 What do Solvation and Solvate Mean? IUPAC Definition: Any stabilizing interaction of a solute by solvent molecules, or the solvent interaction of solvent with groups of an insoluble material. C 60. m-xylene crystalline solvates L. Wang et al., Science 2012, 337, 825

Preparation of Fullerene Solvates C 60. m-xylene solvates C 60. 4C 6 H 6 solvates L.

, Science 2012, 337, 825 (TMDTDM-TTF) 2 C 60 (CS 2 ) 3 solvates (1) Solvent slowly

deuterated C 6 H 6 at 298 K M. F. Meidine et al., J. Chem. Soc. Commun. 1992, 1534. A. L.

9 Preparation of Fullerene Solvates C 60. m-xylene solvates C 60. 4C 6 H 6 solvates L. Wang et al., Science 2012, 337, 825 (TMDTDM-TTF) 2 C 60 (CS 2 ) 3 solvates (1) Solvent slowly evaporated for 7-10 days (2) Solvates detection - XRD at 104 K and 173 K - NMR with deuterated C 6 H 6 at 298 K M. F. Meidine et al., J. Chem. Soc. Commun. 1992, A. L. Balch et al., J. Chem. Soc. Commun. 1993, 56. J. Klinowski et al., J. Phy. Chem. 1997, 101, 117. R. N. Lyubovskaya et al., Synth. Met. 1997, 88, 85 Air Unstable Rapidly lose solvent by evaporation

10 Fullerene Solvates Exist in Solution State? For Aromatic Solvents C 60 Solvates Crystalline (Dry) DSC (Differential Scanning Calorimetry) C 60 Solution Liquid (Wet) Solution Calorimetry The peaks presented at the same temperature (Incongruent melting point) The same value of enthalpy

11 Fullerene Solvate vs. Temperature Dependent Solubility Van s Hoff relationship For nonpolar organic compounds in nonpolar organic solvent: T max d ln x dt A H RT sol 2 Endothermic x A : mole fraction of solute A ΔH sol : the enthalpy of solution Temperature dependent solubility of C 60 in toluene S. Sawamura, and N. Fujita., Carbon 2007, 45, 965

12 Fullerene Solvate vs. Temperature Dependent Solubility Van s Hoff relationship for solid solvate For C 60 in aromatic solvents: dln xc H 60 sol Hr for T T 2 dt RT the enthalpy of C 60 solution (-) dln xc H 60 sol for T T 2 dt RT max max the enthalpy of decomposition of C 60 solvate (+) C 60. nb(s)=c 60 (s)+nb(liq) T max (Incongruent melting point) Endothermic Exothermic Temperature dependent solubility of C 60 in toluene S. Sawamura, and N. Fujita., Carbon 2007, 45, 965

13 Hypothetical Solubility of C 60 Solubility (IUPAC Definition) Pure C 60 + C 60 solvate The analytical composition of a saturated solution expressed as a proportion of a designated solute in a designated solvent. Van s Hoff relationship for C 60 in aromatic solvents: dln xc H 60 sol Hr for T T 2 dt RT dln xc H 60 sol for T T 2 dt RT max max x x Hypothetical solubility of C 60 at 298 K H r : : : ln x H r R Tmax 1 ln x measured saturated mole fraction of C 60 mole fraction of C 60 in hypothetical solution enthalpy of decomposition of C 60 solvate (+) A. L. Smith et al., J. Phys. Chem. B 1999, 103, 1339.

14 Hypothetical Solubility of C 60 Hypothetical solubility of C 60 at 298 K x x H T max ln r : : : : x H r R Tmax The impact of the solubility of a solid solvate 1 ln x measured saturated mole fraction of C 60 mole fraction of C 60 in hypothetical solution enthalpy of decomposition of C 60 solvate (+) Incongruent melting temperature of solvate Solvent 10 4 x 10 4 x (hyp) Toluene Benzene ,2-dimethylbenzene ,3-dimethylbenzene Bromobenzene ,2-dichlorobenzene ,3-dichlorobenzene ,3,5-trimethylbenzene ,2,4-trimethylbenzene A. L. Smith et al., J. Phys. Chem. B 1999, 103, 1339.

15 References 1. M. F. Meidine et al., J. Chem. Soc. Commun. 1992, A. L. Balch et al., J. Chem. Soc. Commun. 1993, R. S. Ruoff et al., Nature 1993, 362, V. Eletskii et al., J. Phy. Chem. 1994, 98, A. L. Smith et al., J. Phys. Chem. B 1996, 100, J. Klinowski et al., J. Phy. Chem. B 1997, 101, Y. Marcus, J. Phy. Chem. B 1997, 101, R. N. Lyubovskaya et al., Synth. Met. 1997, 88, M. V. Korobov et al., Thermo. Acta 1997, 299, A. L. Smith et al., J. Phys. Chem. B 1998, 102, A. L. Smith et al., J. Phys. Chem. B 1999, 103, Y. Marcus et al., J. Phy. Chem. B 2001, 105, N. V. Avramenko et al., J. Therm. Ana. Calorim. 2006, 84, S. Sawamura, and N. Fujita., Carbon 2007, 45, K. N. Semenov et al., J. Chem. Eng. Data 2010, 55, L. Wang et al., Science 2012, 337, 825.

MODEL FOR PREDICTING SOLUBILITY OF FULLERENES IN ORGANIC SOLVENTS. Speaker: Chun I Wang ( 王俊壹 )

MODEL FOR PREDICTING SOLUBILITY OF FULLERENES IN ORGANIC SOLVENTS Speaker Chun I Wang ( 王俊壹 ) 2014.11.03 Thermodynamics Concept of Fullerenes Solubility in Organic Solvents Fundamental Thermodynamics G