Formation constants of copper(I)-olefin complexes in aqueous solution

A simple kinetic method has been applied to measure the formation constants of aqueous copper(I) with fumaronitrile, dimethyl fumarate, and fumaric and maleic acids. At 0.14 M ionic strength, the values of β 1 are (0.85 ′0.02) x 10 3 , (6.1 ′ 0.1) x 10 3 , (7.3 ′ 0.1) x 10 3 , and (2.2 ′ 0.4) x 10 3 M - 1 , respectively. The values for the last two olefins are compared to previous results. Values of β 1 for hydrogen maleate and β 2 for fumaronitrile also have been determined. A reanalysis of much earlier work has been done, and all the results are discussed in terms of the effect of substituents on the olefin on the β 1 values. The structure of bis(fumaronitrile)copper(I) nitrate also is reported. The nitrile is N-coordinated to copper(I), which has a distorted tetrahedral geometry, while the overall structure consists of macrocyclic Cu 6 (fumaronitrile) 6 rings which extend in three dimensions.