Induced spin moments in quasi-one-dimensional halogen-bridged mixed metal complexes of nickel and palladium

Spin susceptibility $\ensuremath{\chi}$ obtained by electron spin resonance in quasi-one-dimensional halogen-bridged mixed metal complexes ${\mathrm{Ni}}_{1\ensuremath{-}x}{\mathrm{Pd}}_{x}(\mathrm{cyclohexandiamine}{)}_{2}{\mathrm{Br}}_{3}$ $(0l~xl~1)$ shows a crossover from Curie-like to weakly temperature-dependent behaviors above around 200 K. The values of $\ensuremath{\chi}$ show a clear enhancement from the linear summation of susceptibilities of Ni and Pd fractions of pure cases, without enhancement of Curie-spin concentration, providing strong evidence for the conversion of nonmagnetic ${\mathrm{Pd}}^{2+}\ensuremath{-}{\mathrm{Pd}}^{4+}$ states into magnetic ${\mathrm{Pd}}^{3+}$ states in mixed metal chains.