William O. Ogini

A convenient synthesis of bis(tri-t-butylphosphine)platinum(0) and its oxidative addition and ligand exchange reactions

Summary Pt[P(t-Bu)3]2 (I) is prepared in high yield from a facile reaction of P(t-Bu)3 with K2PtCl4. Its oxidative addition reactions with CHCl3, CH2Cl2, MeI, and I2, and substitution reactions with CO, M(CO)6 (M=Cr, Mo, W), and t-BuNC have been investigated. Reaction with CHCl3 affords trans-PtHCl[P(t-Bu)3]2 (II) and [ Pt ( µ − Cl ) { P ( t − Bu ) 2 CMe 2 C ︹ H 2 } ] 2 (III), and reaction with CH2Cl2 yields PtCl { P ( t − Bu ) 2 CMe 2 C ︹ H 2 } P(t-Bu) 3 (IV). Pt2Me2(μ-I)2[P(t-Bu)3]2 (VI) and P(t-Bu)3-MeI are formed in the reaction of I with MeI. VI undergoes intramolecular metalation to give [ Pt ( µ − I ) { P ( t − Bu ) 2 CMe 2 C ︹ H 2 } ] 2 (V), and CH4. Reaction of I with I2 results in the formation of V, trans-PtHI[P(t-Bu)3]2 (VII) and P(t-Bu)3I2. CO readily displaces one phosphine from I to give Pt3[P(t-Bu)3]3(CO)3 (VIII). I reacts with M(CO)6 to afford VIII and M(CO)5P(t-Bu)3. t-BuNC replaces both the phosphines from I to give Pt3(t-BuNC)3(μ-t-BuNC)3 (IX).

Preparation and facile intramolecular metalation reactions of bis(tri-t-butylphosphine)platinum(II) hydrides

Bis(tri-t-butylphosphine)platinum(II) hydrides, trans-HPtX(P-t-Bu3)2 (where X  Cl, Br, I and CF3CO2) and trans-H2Pt(P-t-Bu3)2, have been prepared and characterized. These hydrides, unlike platinum(II) hydrides containing less bulky phosphines, undergo facile intramolecular metalation to form the internally metalated complexes [t-Bu2PC(CH3)2CH2 ] PtX(P-t-Bu3) and [{t-Bu2PC(CH3)2CH2}PtH]2, respectively.

Structural studies of steric effects in phosphine complexes. Part 3. The synthesis, characterization, and molecular structure of diacetato[tris(t-butyl)phosphine]mercury(II)

The title complex has been synthesized and found to crystallize in the monoclinic space group P21/c with a= 12.326(5), b= 10.938(3), c= 16.005(3)A, and β= 111.16(1)°. The structure has been solved from diffractometer data using Patterson and Fourier techniques and refined by least-squares methods to a final R of 0.049 for 1 478 independent observed reflections. The geometry at the mercury atom is distorted trigonal bipyramidal with three strong bonds forming a trigonal plane [Hg–P 2.371 (4). Hg–O(2) 2.25(1), and Hg–O(4) 2.27(1)A] and the remaining oxygens of the asymmetrically bidentate acetate groups above and below this plane [Hg–O(1) 2.66(2) and Hg–O(3) 2.58(1)A]. Other mean dimensions include P–C 1.90(2)A, Hg–P–C 106.8(5)°, and C–P–C 112.0(7)°. A ligand profile for PBut3 is given and the maximum cone angle for the ligand is 187(2)°.

Stabilization of platinum(II) hydrides by tri-t-butylarsine; facile syntheses of stable trans-PtH2[As(t-Bu)3]2 and trans-PtHX[As(t-Bu)3]2 complexes

Abstract trans -PtH 2 [As(t-Bu) 3 ] 2 was prepared in very good yield by afacile reaction of K 2 PtC1 4 with As(t-Bu) 3 in alkaline ethanol. Treatment of trans -PtH 2 [As(t-Bu) 3 ] 2 with CF 3 CO 2 H or HCI afforded trans -PtH(O 2 CCF 3 )[As(t-Bu) 3 ] 2 or trans -PtHCl[As(t-Bu) 3 ] 2 . respectively, in almost quantitative yield.