Reactions of Bis(triphenylphosphonio)isophosphindolide Salts with Mercury(II) Compounds:  Coordination Induced Addition and Oxidation Reactions and Synthesis of a Monomeric 1:1 Complex of the Type [R₂(R‘O)P]HgBr₂

Abstract

Bis(triphenylphosphonio)isophosphindolide triflate (1[CF(3)SO(3)]) reacted with HgCl(2) and H(2)O or MeOH to give a phosphinito complex which was converted with excess HgCl(2) into the dimercury complex 5. In contrast, methanolysis of 1[X] (X = CF(3)SO(3), Br) in the presence of Hg(OAc)(2) afforded the phosphonium cation 9. A mercury complex 8 was isolated for X = Br as a reaction intermediate. Salts of a macrocyclic cation with a constitution similar to that of 9 were obtained by reaction of 1[CF(3)SO(3)] with Hg(OAc)(2) and triethylene glycol. The products were characterised by (1)H, (13)C, and (31)P NMR spectroscopy; in addition, (199)Hg NMR data of some complexes were obtained from 2D (31)P,(199)Hg shift correlations. Complexes 5 (space group P2(1)2(1)2(1), Z = 4, a = 12.449(2) Å, b = 17.583(3) Å, c = 23.111(3) Å, V = 5058.8(14) Å(3), 8917 reflections refined to R(w2) = 0.103) and 8 (space group C2/c, Z = 8, a = 20.028(2) Å, b = 15.513(2) Å, c = 30.247(8) Å, beta = 91.91(1) degrees, V = 9392(3) Å(3), 7955 reflections refined to R(w2) = 0.177) were further characterized by single crystal X-ray diffractommetry. Compound 8 is the first example of a monomeric complex of the type LHgX(2) (L = phosphine donor, X = halogen); formation of a halide bridged dimer is presumably prevented by the extraordinarily sterically demanding ligand. A reaction mechanism for the formation of 5 and 8 is proposed which involves the formation of mercury complexes of 1 as the initial step.

Halogenation of Bis(phosphonio)isophosphindolide Salts: Oxidation versus Substitution

“…tem [8] . The magnitudes of The oxidation of the bis(phosphonio)isophosphindolide cation 1 to the 1,1-dihalogeno derivatives 6b, 6c and 8a, as upfield shifts with respect to 1, 5b as were previously found for the 1,1-dialkoxy-substituted cations 2 [2] , suggesting a well as the corresponding retro reaction (that is reduction of the formed products to give 1, 5a and 5b, respectively) pronounced ylidic character for the exocyclic PϪC bonds. As in 5b, the resonance of the 4-H/7-H atoms of 6c and 8c resemble similar reactions of phosphinines [3] [7] .…”

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[2] . This reaction is related to the conversion ence of the unchanged cation 1, UV/Vis and Raman spectra of σ 2 ,λ 3 -phosphinines 3 into 1,1-dialkoxy-σ 4 ,λ 5 -phosphinshowed bands attributable to I 3 Ϫ anions [UV/Vis: λ max ϭ ines 4 (Scheme 1), which takes place under similar con-361, 294 nm (ref.

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Phosphaalkene, phospholyl and phosphinine ligands: New tools in coordination chemistry and catalysis

“…Thus it was shown that reaction with HgCl 2 affords complexes that formally result from a 1.1-oxidative addition at the diccordinate phosphorus center. In the presence of alcohols zwitterionic systems such as 131 are formed (Figure 27) [127]. The bis (phosphonio)benzophophospholide backbone was also employed to build phosphine fucntionalized systems which features two phosphorus centers with notably different electronic properties.…”

Assessing the Ligand Properties of NHC‐Stabilised Phosphorus(I) Cations

“…[2][3][4][5] As early as 1973, Dimroth reportedt hat silver and mercury complexes of benzimidazolylphosphamethine cyanines could be isolated as solids. [6] However,u nlike otherl ow-coordinate phosphoruscontaining compounds,s uch as phosphides, [7][8][9][10][11] phospholides, [12,13] phosphinidenes, [14][15][16][17][18][19][20][21][22] phosphinines, [23][24][25][26][27][28][29][30] phosphaalkenes, [31][32][33][34][35] isophosphindoliums [36][37][38][39] and phospheniums, [40][41][42][43][44][45] which have all seen extensive development as ligandso ver the years, the coordinationc hemistry of phosphamethine cyanine cations has remained virtually unexplored since Dimroth's seminalwork.…”