Abstract
Reactions of Cl(2)P(CH(2))(3)PCl(2) and p-MgBrC(6)H(4)X (X = a/OMe, b/OtBu, c/tBu, d/SiMe(3)) give the diphosphines (p-XC(6)H(4))(2)P(CH(2))(3)P(p-C(6)H(4)X)(2) (1a-d; 47-66%). Additions of 1a,d to (COD)PtCl(2) yield (CH(2)(CH(2)P(p-C(6)H(4)X)(2))(2))PtCl(2) (2a,d; 62-88%), which upon reaction with butadiyne (2 equiv; HNEt(2)/cat. CuI) give (CH(2)(CH(2)P(p-C(6)H(4)X)(2))(2))Pt((C≡C)(2)H)(2) (3a,d; 34-76%). Alternatively, 3a-d can be accessed from trans-(p-tol(3)P)(2)Pt((C≡C)(2)H)(2) and 1a-d (30-87%). Reactions of (p-tol(3)P)(2)PtCl(2) and H(C≡C)(2)SiR(3) (2 equiv, HNEt(2)/cat. CuI; R = Me/Et/iPr) give trans-(p-tol(3)P)(2)Pt((C≡C)(2)SiR(3))(2) (77-95%), and subsequent additions of 1a,b,d yield the corresponding adducts (CH(2)(CH(2)P(p-C(6)H(4)X)(2))(2))Pt((C≡C)(2)SiR(3))(2) (R/X = Me/OMe, 5a; iPr/OMe, 6a; iPr/OtBu, 6b; iPr/SiMe(3), 6d; 52-95%) and (for 5a) a luminescent diplatinum byproduct with trans Pt((C≡C)(2)SiMe(3))(2) units. 5a and 6b hydrolyze in the presence of F(-) to 3a,b (92-93%). Reaction of 2a and 3a (HNEt(2)/cat. CuI) affords the Pt(4)C(16) polygon ([(CH(2)(CH(2)P(p-C(6)H(4)OMe)(2))(2))Pt(C≡C)(2)](4) as an H(2)NEt(2)(+) Cl(-) adduct (66%). The (13)C{(1)H} NMR spectra of 3a-d, 5a, and 6a,b,d feature complex AMXX' (CPtPP') spin systems, and simulations allow J values to be extracted. The crystal structures of 2a, 3a,b,d, 5a, and 6a are determined and analyzed.