Synthesis and Ligand Substitution Reactions of a Mesitylphosphido-Bridged Platinum(II) Dimer

Abstract

The stable primary phosphine complexes trans-M(PH(2)Mes)(2)Cl(2) (1, M = Pd; 2, M = Pt; Mes = 2,4,6-(t-Bu)(3)C(6)H(2)) were prepared from Pd(PhCN)(2)Cl(2) and K(2)PtCl(4), respectively. Reaction of Pt(COD)Cl(2) (COD = 1,5-cyclooctadiene) with less bulky arylphosphines gives the unstable cis-Pt(PH(2)Ar)(2)Cl(2) (3, Ar = Is = 2,4,6-(i-Pr)(3)C(6)H(2); 4, Ar = Mes = 2,4,6-Me(3)C(6)H(2)). Spontaneous dehydrochlorination of 4 or direct reaction of K(2)PtCl(4) with 2 equiv of PH(2)Mes gives the insoluble primary phosphido-bridged dimer [Pt(PH(2)Mes)(&mgr;-PHMes)Cl](2) (5), which was characterized spectroscopically, including solid-state (31)P NMR studies. The reversible reaction of 5 with PH(2)Mes gives [Pt(PH(2)Mes)(2)(&mgr;-PHMes)](2)[Cl](2) (6), while PEt(3) yields [Pt(PEt(3))(2)(&mgr;-PHMes)](2)[Cl](2) (7), which on recrystallization forms [Pt(PEt(3))(&mgr;-PHMes)Cl](2) (8). Complex 5 and PPh(3) afford [Pt(PPh(3))(&mgr;-PHMes)Cl](2) (9). Addition of 1,2-bis(diphenylphosphino)ethane (dppe) to 5 gives the dicationic [Pt(dppe)(&mgr;-PHMes)](2)[Cl](2) (10-Cl), which was also obtained as the tetrafluoroborate salt 10-BF(4)() by deprotonation of [Pt(dppe)(PH(2)Mes)Cl][BF(4)] (11) with Et(3)N or by reaction of [Pt(dppe)(&mgr;-OH)](2)[BF(4)](2) with 2 equiv of PH(2)Mes. Complexes 8, 9, and 10-Cl.2CH(2)Cl(2).2H(2)O were characterized crystallographically.

Zur oxidativen Addition von komplexierten Phosphanen bzw. Arsanen an Platin(0)‐Komplexen

“…In trans-2 betra È gt die Bindungsla È nge P±Pt des verbru È ckenden Phosphanidoliganden 235.9(2) pm und ist damit nur geringfu È gig la È nger als im P(H)Mes-verbru È ckenden Komplex [(Ph 3 P)Pt(H)(l-PHMes) 2 Pt-(Cl)PPh 3 ] (231.8(2) pm) [10]. 2).…”

Gold Phosphide Complexes

“…Thus, the chemistry of phosphido-bridged derivatives of the main group elements [1][2][3] or transition metals [4][5][6] has been a matter of interest for various research groups in the last few years. While there are many phosphido complexes with metals, mainly of groups 6 7-12 or 10, [13][14][15][16][17][18][19][20] the chemistry of gold derivatives has experienced less progress in this field of research in spite of the possible catalytic behaviour of di-and polynuclear phosphido-bridged compounds. 21 This is an interesting field of research, because the substitution of one or more protons by metal atoms allows the synthesis of homo-or heteropolynuclear compounds in which the presence of a small bridging atom, such as phosphorus, may give rise to intermetallic contacts, which, as is known, are often responsible for surprising and interesting optical properties, such as luminescence, area with an increasing importance in the last years.…”

Reactivity of (Ferrocenylmethyl)phosphine toward Palladium and Platinum Chlorides. X-ray Structure of [Pd(PH2CH2Fc)Cl(μ-PHCH2Fc)]4(Fc = Ferrocenyl), a Unique Complex Containing a Pd4P4Cycle

“…The metal environ- The signals of the 31 P{ 1 H} NMR spectrum described above can be easily attributed to the coordinated (ferrocenylmethyl)-phosphines (δ -34.0) and to the bridging phosphanides (δ -6. 8). The large value of the 2 J P-P ) 409 Hz is typical for coupling between trans P atoms.…”

“…The high nuclearity of 2 is worth noticing, since in all the known cases, dehydrohalogenation from primary (and secondary) phosphine Pd(II) complexes led to dinuclear compounds. 5,6,8,22 The structure of 2, together with the atom labeling scheme, is shown in Figure 2.…”