ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The title cation ( = Ni2L+3) is formed in a variety of reactions (Schemes 1 and 2) in systems containing Ni2+ and (2-thiolatoethyl)-diphenylphosphine (= L-) in the absence of coordinating anions at Ni2+/L- ratios 〉 0.5 in apolar or moderately polar media. Solid [Ni2L3]CIO4 and [Ni2L3]BPh4 have been isolated. Job's plots confirm the Ni2L+3- stoichiometry in solution. 31P-NMR data are consistent with ≥ 97% Ni2L+3 (vs. ≤ 3% of hypothetical Ni3L2+4) at equilibrium and support the suggested configuration (Fig. 2). The equilibrium between NiL2 + NiL2Br2 and Ni2L+3 + Br- varies with the solvent composition in CH23Cl2/EtOH mixtures. The rate of formation of Ni2L2Br2 from Ni2L+3 and bromide (in high excess) in CH2Cl2 is first-order in [Ni2L+3]tot but depends on the ratio [Bu4NBr]tot/[Ni2L3 · ClO4]tot, even at a high excess of bromide. This is interpreted by efficient competition in ion-aggregate formation between the small perchlorate concentration introduced as the counterion of Ni2L+3, and the large excess of bromide.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19840670304
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