The various Ni(I) species formed by reduction and adsorbate interactions in silicoaluminophosphate-11, synthesized by incorporation of Ni(II) in the synthesis mixture (NiAPSO-11) and formed by partial ion exchange of H(I) by Ni(II) (NiH-SAPO-11), were studied by electron spin resonance. After dehydration at temperatures above 773 K one Ni(I) species is observed in NiAPSO-11, while this treatment does not generate any Ni(I) species in NiH-SAPO-11. Two distinct Ni(I) species, assigned as isolated Ni(I) and Ni(I)-(H-2)(n), are observed in both NiAPSO-11 and NiH-SAPO-11 after reduction in hydrogen at 573 K. Ni(I)-(O-2)(n) species are produced both in hydrogen-reduced NiAPSO-11 and in NiH-SAPO-11 after adsorption of water, indicating water decomposition on the Ni-containing oxide surface. Ni(I) complexes with methanol show some differences in the g parameters between NiAPSO-11 and NiH-SAPO-11. A more significant difference between NiAPSO-11 and NiH-SAPO-11 in nickel ion coordination to adsorbates is seen with nonpolar adsorbates. The adsorption of carbon monoxide onto NiAPSO-11 and NiHSAPO-11 produces Ni(I)-(CO)(n) with n = 1-3. The Ni(I)-(CO)(1) species is not observed in NiH-SAPO-11. The rate of ethylene adsorption onto NiAPSO-11 is 1000-fold more rapid than onto NiH-SAPO-11. The contrasting ESR characteristics of Ni(I) in NiAPSO-11 and NiH-SAPO-11 suggest that Ni(I) in NiAPSO-11 is in a framework site.