The signs of spin–spin coupling constants in square planar complexes of platinum(II)

Abstract

Heteronuclear magnetic double resonance techniques are used to establish the signs of the spin–spin coupling constants in cis- and trans-dichlorobis(triethylphosphine)platinum(II). The signs are: ¹J(¹⁹⁵Pt–³¹P), positive; ³J(¹⁹⁵Pt⋯CH₂), positive; ²J(³¹P–CH₂), negative. These signs probably apply to square planar complexes of platinum(II) in general, and the large value of 552 p.p.m. is found for the ¹⁹⁵Pt chemical shift between the two isomers.