Dynamics of ternary complex formation in the reaction of diaquoanthranilato-N, N-diacetatonickelate(II) with 2,2′-bipyridine and 1,10-phenanthroline

✍ Scribed by Asim K. Das

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 494 KB
• Volume: 28
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/(sici)1097-4601(1996)28:4<275::aid-kin5>3.0.co;2-s

✦ Synopsis

Dynamics of ternary complex formation in the reaction of diaquoanthranilato-N , Ndiacetatonickelate(l1) with 2,2'-bipyridine and I ,lo-phenanthroline. Ni(adal( H2012-

and L = bipy or phen

The kinetics of formation of ternary complexes by diaquoanthranilato-N, Ndtacetatonickelate[ i l ) , [Nl(ada)[H20)]-with 2.2'-bipyridine [bipy) and I ,lo-phenanthroline [phen I have been studied under pseudo-first-order conditions containing excess bipy or phen by stopped-flow spectrophotometry in the pH range 7 1-78 at 25°C and I = 0.1 mol dm-3 In each case, the reaction is first-order with respect to both Ni(ada)-and the entering ligand [ i . e , bipy, phen) The reactions are reversible The forward rate constants are k ~~~~~~~( p h c n ] = 1.87 X 10' dm' m O l -' s -' , and the reverse rate constants are k N l ( a d a ) -2.0 s -I . The corresponding stability constants of ternary complex formation are-log K N , ( a d a ) , ~l p v ] = 2.94 and Alog K M = -4.13. log K N l , a d s ) ( p h e n l = 2.97, and Alog K M = -5.03 The observed rate constants and huge drops in stability constants in ternary complex formation agree well Nilada) kN,,adnl(h,py, = 0.87 X lo3 dm3 mol-' s-', Ni(ada11, hipyl Ni(adal( phen) -= 1.0 s-' and kNl(&) Ni(add1 Ni(ada1