Uncommon co-ordinating agents—I

Transition‐Metal Complexes with Bidentate Ligands Spanning trans‐Positions. III. Preparation and solution studies of complexes [MX(1)] (M = Cu, Ag and Au; X = anionic ligand; 1 = 2, 11‐bis(diphenylphosphinomethyl)benzo[c]phenanthrene)

“…-The chemistry of tertiary phosphine and ditertiaryphosphine complexes of copper(I), silver(1) and gold(1) is characterised by the wide range of 5toichiometric and structural types obtained [l-31. This results from the widespread occurrence of such effects as bridging by anionic ligands and by diphosphines [4-91, the formation of cluster compounds [4] [lo] and the formation of a variety of ionic Complexes based on the cation [ML4]+ in which the anion may also contain the coinage metal [4] [5] [ 111 [12] (Lz = two monodentate phosphines or a bidentate diphosphine; M = Cu, Ag, Au).…”

Lead(ii) nitrate and hexafluorosilicate complexes with neutral diphosphine coordination

“…The in situ oxidation of diphosphine ligands in the presence of heavy p-block metals has been reported before; 5 for example, the oxidation of the 1 : 1 adduct of BiCl 3 and Ph 2 PCH 2 PPh 2 to the crystallographically identified [BiCl 3 {Ph 2 P-(O)CH 2 P(O)Ph 2 }] 2 having occurred when trying to grow crystals of the phosphine complex. 18 Interestingly, the in situ oxidation of diphosphine ligands has also been reported with Pb(II), when a few crystals of [{(Pb 3 (µ-I) 6 )(Ph 2 (O)P(CH 2 ) 2 P(O)-Ph 2 ) 2 }]·EtOH were obtained from the solvothermal reaction of PbI 2 with KI, I 2 and Ph 2 P(CH 2 ) 2 PPh 2 . Attempts to increase the yield of the phosphine oxide complex by introducing H 2 O 2 into the reaction generated [{Pb 2 (µ-I) 2 (µ 3 -I) 2 }{Ph 2 (O)P(CH 2 ) 2 -P(O)Ph 2 }].…”

“…The IR spectrum of the bulk solid confirms the presence of the SiF 6 2− group, although the anion coordination mode cannot be reliably identified. 16 The stretching mode is significantly broadened, indicating that the Pb-F interactions are too weak to lower the symmetry of the fluoroanion sufficiently to give resolved splittings.…”

“…The crystal structure (Fig. 3a) shows the diphosphine to be asymmetrically chelating, with a short Pb-F bond (d(Pb1-F5) = 2.573(3) Å) to a κ 1 -coordinated SiF 6 2− group and a further bond to a water molecule, so that overall the core molecular geometry is very similar to that of [Pb{o-C 6 H 4 (PMe 2 ) 2 }(NO 3 ) 2 ] (Fig. 2a), although the disparity in Pb-P bond lengths is greater (∼0.03 Å) and the F-Pb-O angle is large (154.76(11)°).…”

“…4 However, whilst phosphine complexes of most heavy main group metals (including Hg(II), In(III), Sn(II), Sn(IV) and Bi(III)) are well established, 5 the coordination chemistry of lead(II) with neutral phosphines is extremely limited. 5 While [Pb{Et 2 P(CH 2 ) 2 PEt 2 }Br 2 ] and [Pb{Et 2 P-(CH 2 ) 2 PEt 2 } 2 ](ClO 4 ) 2 were claimed in 1960, characterisation was limited to partial microanalysis, 6 and the only structurally characterised examples of neutral diphosphine complexes are the lead(II) thiolates [(2,6-Me 2 C 6 H 3 S) 2 Pb] 2 {µ-Ph 2 P(CH 2 ) 2 PPh 2 } and [(2,6-Me 2 C 6 H 3 S) 2 Pb] 3 {Me 2 P(CH 2 ) 2 PMe 2 }. 7 The latter contains a chain of the three lead centres linked by thiolate bridges, with the Me 2 P(CH 2 ) 2 PMe 2 chelating to the central Pb.…”