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Probing the electronic communication of linear heptanickel and nonanickel string complexes by utilizing two
Shao-An Hua1, Isiah Po-Chun Liu, Hasan Hasanov
1Department of Chemistry, National Taiwan University, Taipei, Taiwan.
Dalton Transactions (Cambridge, England : 2003)
|April 8, 2010
Summary
Synthesized nickel string complexes show weaker electronic communication as they get longer. This electronic communication decreases with more inner diamagnetic nickel ions in these metal frameworks.
Area of Science:
- Coordination Chemistry
- Inorganic Chemistry
- Materials Science
Background:
- Nickel string complexes are polynuclear metal compounds with potential applications in molecular electronics.
- Understanding electronic communication in these extended metal frameworks is crucial for designing new materials.
Purpose of the Study:
- To synthesize and characterize two new extended nickel string complexes, [Ni(7)(bnapy)(4)Cl(2)](Cl)(2) (2) and [Ni(9)(bnapya)(4)Cl(2)](PF(6))(2) (3).
- To investigate the electronic communication between redox-active nickel units within these complexes.
- To correlate the electronic communication with the structural elongation and the number of inner diamagnetic nickel ions.
Main Methods:
- Synthesis and characterization of nickel string complexes.
- Magnetic measurements to determine magnetic coupling constants (J).
- Electrochemical analysis (cyclic voltammetry) to measure the difference between consecutive one-electron oxidation peaks (DeltaE(1/2)).
Main Results:
- Complexes 2 and 3, containing two redox-active [Ni(2)(napy)(4)](3+) units, were successfully synthesized.
- Antiferromagnetic coupling between the nickel units weakens with increasing framework length (J = -13.21 cm(-1) for 2 and J = -1.48 cm(-1) for 3).
- The DeltaE(1/2) values for complexes 2 (110 mV) and 3 (84 mV) are significantly smaller than that of the pentanickel analogue (300 mV), indicating reduced electronic communication.
Conclusions:
- Electronic communication in nickel string complexes is inversely related to the length of the metal framework.
- Increasing the number of inner diamagnetic nickel ions diminishes the electronic communication between the redox-active units.
- These findings provide insights into the structure-property relationships of extended nickel-based molecular materials.
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