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Volumn 118, Issue 50, 1996, Pages 12614-12623

Predicting the relative stabilities of multiparticle hydrogen-bonded aggregates based on the number of hydrogen bonds and the number of particles and measuring these stabilities with titrations using dimethyl sulfoxide

Author keywords

[No Author keywords available]

Indexed keywords

BARBITURIC ACID DERIVATIVE;

EID: 0030481446     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja962768i     Document Type: Article
Times cited : (78)

References (71)
  • 26
    • 85033180492 scopus 로고    scopus 로고
    • note
    • Tm is a function of the number of hydrogen bonds, HB, in the complex; with double stranded DNA, N is constant and equals two.
  • 28
    • 85033186823 scopus 로고    scopus 로고
    • note
    • 3, there appeared a new peak at approximately 11.5 ppm that seemed to grow with increasing mole fraction of methanol, then disappeared completely at 100% DMSO. It is possible that this peak represents a partly dissociated aggregate and that a three-step model more accurately describes the dissociation of certain of the aggregates.
  • 30
    • 85033164232 scopus 로고    scopus 로고
    • note
    • The precise shape of the peak in the GPC trace is a complex function of the rate of disassembly (relative to the time of the GPC experiment), of the mechanism of disassembly, and of the solubility of the components (the CA components-especially those containing two and three CA groups-have low solubility in chloroform). For insoluble CA components, such as those in aggregates 1-3 and 8, the shape of the GPC traces implies a greater stability than determined from titrations using DMSO-experiments that we feel are more accurate than any of the other methods discussed. Specifically, aggregates 1 and 8 give reasonably sharp GPC traces but are dissociated by low mole fractions of DMSO.
  • 36
    • 0004615588 scopus 로고
    • Bond strain occurs when the conformation adopted on assembly requires that bond lengths, bond angles, and torsional angles deviate from values in the uncomplexed particles. We believe that differences in BS are related to the degree of planarity (DP) of the rosette; we have addressed this issue in Chin, D.; Gordon, D. M.; Whitesides, G. M. J. Am. Chem. Soc. 1994, 116, 12033.
    • (1994) J. Am. Chem. Soc. , vol.116 , Issue.THIS ISSUE , pp. 12033
    • Chin, D.1    Gordon, D.M.2    Whitesides, G.M.3
  • 42
    • 85033160469 scopus 로고    scopus 로고
    • note
    • In systems other than our own, VDW and CC interactions may not be negligible. If the energies of VDW and ES are either (i) proportional to the number of hydrogen bonds or (ii) similar in magnitude among the aggregates, then differences in HB are still proportional to the relative energies of assembly.
  • 43
    • 85033170865 scopus 로고    scopus 로고
    • note
    • In self-assembling systems based on charge-charge interactions or metal-ligand chelates, the analysis would be parallel to that reported here, with the number of charge-charge interactions or metal-ligand interactions replacing HB.
  • 50
    • 0004057516 scopus 로고
    • A Series of Books in Chemistry, W. H. Freeman and Company: San Francisco
    • Rice, O. K. Statistical Mechanics, Thermodynamics and Kinetics; A Series of Books in Chemistry, W. H. Freeman and Company: San Francisco, 1967; pp 37-80.
    • (1967) Statistical Mechanics, Thermodynamics and Kinetics , pp. 37-80
    • Rice, O.K.1
  • 51
    • 85033178170 scopus 로고    scopus 로고
    • note
    • If the change in conformational entropy is either (i) proportional to the number of particles, (N-1) or (ii) of similar magnitude in the aggregates, then differences in (N-1) will still be predictive of relative entropic cost of assembly.
  • 53
    • 85033182250 scopus 로고    scopus 로고
    • note
    • We choose (N-1) because this term describes accurately the number of units of translational-rotational entropy that are lost on assembly.
  • 69
    • 85033159169 scopus 로고    scopus 로고
    • note
    • Trace water was not possible to avoid even in fresh bottles of deuterated solvent, and was present in proportion to the mole fraction of DMSO. Because the ratio of DMSO to water was approximately 20000:1, and because the DMSO, as a hydrogen bond acceptor, is comparable to water, the contribution of this trace water to dissociation of the aggregate was ignored.
  • 70
    • 85033169545 scopus 로고    scopus 로고
    • note
    • Certain CA derivatives-especially those containing two or three CA groups-precipitate slightly from solution when not part of a stable assembly; this precipitation may thermodynamically lessen the likelihood of formation of stable aggregates, and the value of the mole fraction of DMSO required for dissociating the aggregate may be slightly underestimated.
  • 71
    • 85033163564 scopus 로고    scopus 로고
    • note
    • DMSO.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.