The reaction of 1,1-(PMe(2)Ph)(2)-closo-1,2,3-PdAs2B9H9 (A) with (1)BuNC formed low yields of 5-CN-1,1-(PMe(2)-Ph)(2)-closo-1,2,3-PdAs2B9K8 (2) and/or 1-(t)BuNC-5-CN-1-(PMe(2)Ph)-closo-1,2,3-PdAs2B9H8 (3). The use of ((t)BuNC)(2)PdCl2 as a reagent in this reaction gave an improved yield of compound 3. Similar reaction of 1,1-(PMe(2)Ph)(2)-closo-1,2,3-PdC2B9H11 (4) with ((t)BuNC)(2)PdCl2 gave 4.5-(CN)(2)-1,1-(PMe(2)Ph)(2)-closo-1,2,3-PdC2B9H9 (5). Reaction of A with (PMe(2)Ph)(2)P(CN)(2) gave 1-CN-1,5-(PMe(2)Ph)(2)-closo-1,2,3-PdAs2B9H8 (1) in low yield. Compounds 2, 3, and 5 were characterized by X-ray diffraction studies. Compound 2 consisted of bright purple crystals of monoclinic space group P2(1)/n, with a = 12.460(2) Angstrom, b = 11.583(2) Angstrom, c = 19.114(4) Angstrom, beta = 107.31(1)degrees, and Z = 4. The structure was determined by conventional heavy-atom methods and refined to a final value of R = 0.0432 (3899 reflections) and R(w) = 0.0458. Compound 3 consisted of magenta plates with triclinic space group , with a = 11.586(3) Angstrom, b = 11.813(3) Angstrom, c = 9.799(2) Angstrom, alpha = 95.33(1)degrees, beta = 114.58(1)degrees, gamma = 80.17(1)degrees, and Z = 2. The structure was determined by conventional heavy-atom methods and refined to a final value of R = 0.0235 (3323 reflections), R(w) = 0.0245. Compound 5 consisted of red needles with monoclinic space group P2(1)/n, with a = 10.383(2) Angstrom, b = 18.875(3) Angstrom, c = 13.682(2) Angstrom, beta = 105.41(1)degrees, and Z = 4. The structure was determined by conventional heavy-atom methods and refined to a final value of R = 0.0362 (3547 reflections), R(w) = 0.0335.