聚氨大环-氰基合钴超分子的转动相关时间及59Co核四极耦合常数的测定——动态激光光散射的应用

波谱学杂志

聚氨大环-氰基合钴超分子的转动相关时间及⁵⁹Co核四极耦合常数的测定——动态激光光散射的应用

周平1*，欧阳植勋2

1.聚合物分子工程教育部重点实验室，高分子科学系，复旦大学，上海 200433;
2.香港中文大学化学系，香港

收稿日期:2003-04-14 修回日期:2003-07-23 出版日期:2003-12-05 发布日期:2003-12-05
作者简介:*通讯联系人：周平，E-mail:Pingzhou@fudan.edu.cn, 电话:+86-21-55664038,传真:+86-21-65640293.
基金资助:
The project was supported by NSFC (No.20274009, 29974004).

DETERMINATION OF ROTATIONAL REORIENTATION CORRELATION TIME AND ⁵⁹Co NUCLEAR QUADRUPOLAR COUPLING CONSTANT OF POLYAMMONIUM MACROCYCLIC COBALTICYANIDE SUPERCOMPLEXES IN DILUTE AQUEOUS SOLUTIONS——An Application of Dynamic Laser Light Scattering Method

ZHOU Ping1*, AU-YEUNG Steve C. F.2

1. The Key Laboratory of Molecular Engineering of Polymers, Ministry of Education. Macromolecular Science Department, Fudan University, Shanghai 200433, China; =
2. Department of Chemistry, The Chinese University of Hong Kong, Hong Kong, China

Received:2003-04-14 Revised:2003-07-23 Online:2003-12-05 Published:2003-12-05
About author:ZHOU Ping:Associate professor& Dr.,Majoring in the field of structure and function of biopolymers, E-mail: pingzhou@fudan.edu.cn,Tel:+86-21-55664038,Fax:+86-21-65640293,*Author to whom correspondence should be addressed.
Supported by:
The project was supported by NSFC (No.20274009, 29974004).

摘要/Abstract

摘要：

对于自旋I>1/2的核，其运动的相关时间τ_c以及核四极耦合常数NQCC是表征分子局部和微观动力学结构的重要参数. 然而，在溶液中，这些参数均难以测定. 该工作以聚氨大环-氰基合钴超分子体系为例，利用在高分子体系中广泛使用的激光光散射技术成功地测量了溶液中超分子络合物［12］aneN₄［Co(CN)₆］, ［18］aneN₆［Co(CN)₆］, ［24］aneN₈［Co(CN)₆］, ［16］aneN₄［Co(CN)₆］, ［24］aneN₆［Co(CN)₆］和［32］aneN₈［Co(CN)₆］的水合半径，从而根
据Stokes-Einstein-Debye理论计算出了分子转动的相关时间τ_c. 这些超分子的水合半径在0.4～0.6 nm之间. 对应的转动相关时间τ_c在3.8～9.5×10^-11 s之间. 这一时间范围对于分子量在300～500的分子，有相当的合理性. 进而，通过测量超分子在稀溶液中的纵向弛豫时间T₁，结合计算出的相关时间τ_c，我们得到了该超分子体系中⁵⁹Co的四极耦合常数，其范围在0.5～2.2 MHz之间. 我们发现，这些超分子在溶液中的四极耦合常数明显小于在固体状态时的值（5～7 MHz）. 导致这一现象很可能的原因是在固体状态下⁵⁹Co核周围的电场梯度是各向异性的，从而有较大的四极耦合常数值. 而在溶液中，由于分子的快速运动，各向异性被平均，因而有较小的四极耦合常数.

Abstract:

The correlation time, τ_c, and the nuclear quadrupolar coupling constant (NQCC) of I>1/2 nuclei are important parameters for characterizing local and microdynamic structures of molecules. However, it is often difficult to determine those constants in solution. In this study, τc and NQCC of the ⁵⁹Co nuclei were determined for a series of supercomplexes [12] aneN₄[Co(CN)₆], [18]aneN₆[Co(CN)₆], [24]aneN₈[Co(CN)₆], [16]aneN₄[CoCN)₆], [24]aneN₆[Co(CN)₆] and [32]aneN₈[Co(CN)₆] in dilute solution. The Dynamic Laser Light Scattering (DLLS) method, which is now widely used in macromolecule research, was first applied to determine the hydrodynamic radii (0.4～0.6 nm) of these molecules. Based on the Stokes-Einstein-Debye equation and the measured hydrodynamic radii, the rotational reorientation correlation times τ_c were calculated. τ_c obtained in this study had a range of 3.8～9.5×10^-11s, which arefairly reasonable for molecules with molecular weights of about 300～500. Finally, NQCC of the ⁵⁹Co nuclei in the supercomplexes were determined by combining the τ_c values calculated and the experimentally measured longitudinal relaxation times, T₁, of the ₅₉Co nuclei. The NQCC values obtained ranged from 0.5 to 2.2 MHz, which are considerably lower than those extracted from solid static NMR lineshape (5 to 7 MHz). The difference is probabl
y due to the structural effects originating from the anisotropy of local electric gradient around ⁵⁹Co nucleus in solid.

Key words: ⁵⁹Co NMR, correlation time, nuclear quadrupolar coupling constant, laser light scattering, supercomplex

中图分类号:

O482.53

周平1*，欧阳植勋2. 聚氨大环-氰基合钴超分子的转动相关时间及⁵⁹Co核四极耦合常数的测定——动态激光光散射的应用[J]. 波谱学杂志.

ZHOU Ping1*, AU-YEUNG Steve C. F.2. DETERMINATION OF ROTATIONAL REORIENTATION CORRELATION TIME AND ⁵⁹Co NUCLEAR QUADRUPOLAR COUPLING CONSTANT OF POLYAMMONIUM MACROCYCLIC COBALTICYANIDE SUPERCOMPLEXES IN DILUTE AQUEOUS SOLUTIONS——An Application of Dynamic Laser Light Scattering Method[J]. Chinese Journal of Magnetic Resonance.

参考文献

［1］Craighead K L, Bryant G R. The insignificance of second coordination sphere interactions in cobalt-59 nuclear magnetic resonance relaxation ［J］. J Phys Chem, 1975, 79: 1602-1603.

［2］Au-Yeung S C F, Eaton D R. The solvent and field-dependence of Co-59 NMR linewidths ［J］. J Magn Reson, 1983, 52: 366-373.

［3］Chacko V P, Bryant R G. Electric-field gradient modulation and nuclear magnetic-relaxation in hexacyanocobaltate ion ［J］. J Magn Reson, 1984, 57: 79-84.

［4］Yamasaki A. Cobalt-59 nuclear-magnetic-resonance spectroscopy in coordination chemistry ［J］. J Coord Chem, 1991, 24: 211-260.

［5］Iida M, Nakamori T, Mizuno Y, Masuda Y. Appreciable effects of ion pairings on the Co-59 electric-field gradient in the NMR relaxation of ［Co(CHXN)₃］³⁺［J］. J Phys Chem, 1995, 99: 4347-4352.

［6］Kirby C W, Puranda C M, Power W P. Cobalt-59 nuclear magnetic relaxation studies of aqueous octahedral Cobalt (Ⅲ) complexes ［J］. J Phys Chem, 1996, 100: 14618-4624.

［7］Chen Z Z, AuYeung S C F. The NMR Spectroscopy of Transition Metals ［J］. Chinese J Magn Reson, 1995, 12: 525-540.

［8］Zhou P, Au-Yeung S C F, Meng Q A. The Second Sphere Interaction in the Supramolecular Complexes Studied by 59Co Solid State NMR ［J］. Acta Phys Chim, 1999, 15: 533-540.

［9］Gillies D G, Sutcliffe L H, Williams A J. Variable-temperature high-pressure investigation of the cobalt-59 NMR spectroscopy of aqueous K₃［Co(CN)₆］［J］. Magn Reson Chem, 2002, 40: 57-64.

［10］Abragam A. Principles of Nuclear Magnetism ［M］. Clarendon Press: Oxford, 1961.

［11］Zhou P, Au-Yeung S C F, Xu X P. A DFT and Co-59 solid-state NMR study of the second-sphere interaction in polyammonium macrocycles cobalt cyanide supercomplexes ［J］. J Am Chem Soc, 1999, 121: 1030-1036.

［12］Lucken E A C. see Spectroscopic and Computational Studies of Supramolecular Systems ［M］. Davies, J E E. (ed), Boston: Kluwer Academic Publishers, 1992.

［13］Homans S W. A Dictionary of Concepts in NMR ［M］. Clarendon Press: Oxford, 1989.

［14］Taube H, Posey F A. The study of a system involving equilibrium between inner sphere and outer sphere complex ions: Co(NH₃)₅H₂O⁺⁺⁺ and SO⁼₄［J］. J. Am. Chem. Soc, 1953, 75: 1463-1467.

［15］Yamasaki A, Yajima F, Fujiwara F. Nuclear magnetic resonance studies on cobalt complexes. I. Cobalt-59 nuclear magnetic resonance spectra of cobalt (Ⅲ) complexes ［J］. Inorg Chim Acta, 1968, 2: 39-42.

［16］Au-Yeung S C F, Eaton D R. A model for estimating Co-59 NMR chemical shifts and line widths and its application to cobalt dioxygen complexes ［J］. Can J Chem, 1983, 61: 2431-2441.

［17］Russell J G, Bryant R G. Nuclear magnetic-relaxation in symmetrical cobalt complexes-ion-pairing effects ［J］. J Phys Chem, 1984, 88: 4298-4302.

［18］Shaw D. Fourier Transform NMR Spectroscopy (2nd ed) ［M］. New York: Elsevier Press, 1984.

［19］Kidd R G, Goodfellow R J. In NMR and The Periodic Table, Harris, B K, Mann, B E (eds), New York: Academic Press, 1978, Chapter. 8.

［20］Gierer A, Wirtz K. Molecular theory of microfriction ［J］. Z Naturforsch, 1953, 8a: 532-538.

［21］Bencini A, Bianchi A, Garcia-Espa[AKn～]a E, et al. Anion coordination chemistry. 2. Electrochemical, thermodynamic, and structural studies on supercomplex formation between large polyammonium cycloalkanes and the 2 complex anions hexacyanoferrate (Ⅱ) and hexacyanocobaltate (Ⅲ) ［J］. Inorg Chem, 1987, 26: 3902-3907.

［22］The elemental analysis results: ［12］aneN₄［Co(CN)₆］, formula: C₈H₂₀N₄H₃［Co(CN)₆］.2H₂O, found: C 39.29 %, H 6.34 %, N 32.74 %, calc.: C 39.41 %, H 6.40 %, N

32.86 %; ［18］aneN6［Co(CN)6］, formula: C12H30N6H2K［Co(CN)6］.4H₂O, found: C 37.06 %, H 6.83 %, N 29.05 %, calc: C 36.85%, H 6.87%, N 28.65%; ［24］aneN8［Co(CN)6］, formula, C16H40N8H6K2 ［Co(CN)6］2Cl2.6H2O, found, C 32.22 %, H 5.71 %, N 27.25 %, calc. C 32.59 %, H 5.65 %, N 27.15 %; ［16］aneN4［Co(CN)6］, formula, C12H28N4H2K［Co(CN)6］, found, C 44.33 %, H 6.12 %, N 29.07 %, calc. C 44.63 %, H 6.20 %, N 28.93 %; ［24］aneN6［Co(CN)6］, formula, C18H42N6H6［Co(CN)6］2.5.5H₂O, found, C 41.23 %, H 6.64 %, N 28.42 %, calc. C 41.05 %, H 6.72 %, N 28.73 %; ［32］aneN8［Co(CN)6］, formula, C24H56N

8H8［Co(CN)6］2Cl2.6H₂O, found, C 40.26 %, H 7.08 %, N 26.10 %, calc. C 40.11 %, H 7.05 %, N 26.10%.

［23］Zhou P, Xue F, Au-Yeung S C F, et al. Crystal structures of ［18］aneN6H2K［Co(CN)6］.4H₂O, ［16］aneN4H2K［Co(CN)6］and ［12］aneN4H3［Co(CN)6］.2H₂O. Insight into the electrostatic and hydrogen-bonding interaction in self-assembling supercomplexes［J］. Acta Cryst B, 1999, 55: 389-395.

［24］Zhou P, Xue F, Au-Yeung S C F. Potassium hexacyanocobaltate, a redetermination ［J］. Acta Cryst C, 1998, 54: IUC9800062.

［25］Chu B. Laser Light Scattering: Basic Principles and Practice［J］. Academic Press: London, 1991.

［26］Provencher S W. Inverse problems in polymer characterization: direct analysis of polydispersity with photon correlation spectroscopy ［J］. Makromol Chem, 1979, 180: 201-209.

［27］Stockmayer W H, Schmidt M. Quasi-elastic light-scattering by semiflexible chains ［J］. Macromolecules, 1984, 17: 509-514.

［28］Weast R C. Handboonk of Chemistry and Physics ［M］. Floride: 67rd Edition,CRC Press, 1986-1987.

［29］Wu C, Chan K K, Xia K Q. Experimental study of the spectral distribution of the light scattered from flexible macromolecules in very dilute solution ［J］. Macromolecules, 1995, 28: 1032-1037.

［30］Compared with 0.35 MHz (ref.7), the effective quadrupolar coupling constant, (e²_qQ/h)’, 0.5 MHz is more reliable because Kirby C. W. et al. (ref. 7) used an estimated correlation time 168 ps in the calculation.

［31］Hertz H G. see Water, A Comprehensive Treatise ［M］. New York: Franks, F. (ed), Plenum Press, 1973, Chapter 7.

［32］Chan C C, Au-Yeung S C F. Interpretation of Co-59 NMR shielding using the hard and soft acid-base concept-Insight into the relative magnitude of the nephelauxetic and the spectrochemical effect ［J］. J Chem Soc, Faraday Trans, 1996, 92: 1121-1128.

[1]	宋华付, 石光明, 徐更光, 王廷增. 芳香族硝基化合物的核四极共振参数的HARTREE-FOCK计算[J]. 波谱学杂志, 2004, 21(2): 186-190.
[2]	周平, 欧阳植勋. 钴超分子络合物中的氢键相互作用——⁵⁹Co核磁共振研究及分子模拟[J]. 波谱学杂志, 2004, 21(1): 1-15.
[3]	席海涛, 孙小强*, 杨扬. 利用核磁共振研究准轮烷的振荡行为[J]. 波谱学杂志, 2001, 18(2): 149-153.
[4]	陈振中, 欧阳植勳. 过渡金属核磁共振谱[J]. 波谱学杂志, 1995, 12(5): 525-540.
[5]	项柏松, 陈炳焕, 万谦. 样品介电性质对ST-ESR谱的影响[J]. 波谱学杂志, 1989, 6(4): 453-460.

聚氨大环-氰基合钴超分子的转动相关时间及⁵⁹Co核四极耦合常数的测定——动态激光光散射的应用

DETERMINATION OF ROTATIONAL REORIENTATION CORRELATION TIME AND ⁵⁹Co NUCLEAR QUADRUPOLAR COUPLING CONSTANT OF POLYAMMONIUM MACROCYCLIC COBALTICYANIDE SUPERCOMPLEXES IN DILUTE AQUEOUS SOLUTIONS——An Application of Dynamic Laser Light Scattering Method

PDF

可视化

摘要/Abstract

引用本文

使用本文

参考文献

相关文章 5

编辑推荐

Metrics

本文评价