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Synthesis of Aminophosphane Complexes: Searching the Boundary between Phosphanide and Phosphinidenoid Complex Chemistry

“…The 31 P NMR spectroscopic data for complex 6 is much closer to that of the diphosphene complex described by Yoshifuji et al [δ = 332 ppm; J (W,P) = 145, 116 Hz]. 9 Hz], we tentatively assigned this signal to the (free) ligand 8. Although the first impression is that of a sterically crowded molecular compound, the P-P bond length in complex 6 al.…”

First synthesis of chloroformylphosphane complexes

“…When phosphinidenoid complex 2a [11] [X = Cl, R = CH(SiMe 3 ) 2 ] was reacted with nearly equimolar amounts of phosgene (20 % solution in toluene) in conditions similar to reported for preparation of analogous organylacylphosphane tungsten(0) complexes [12], no selective formation of the corresponding chloroformylphosphane complex 3a was observed. Instead, rapid formation of dichlorophosphane complex 1a [δ ( 31 P) = 157.6 ppm, 1 J P,W = 330.8 Hz] and some by-products assigned to the chloroformylphosphane complex 3a [δ ( 31 P) = 129.6 ppm, 1 J P,W = 296.3 Hz], chlorophosphane complex 4a [13] [δ ( 31 P) = 53.7 ppm, 1 J P,W = 268.8 Hz, 1 J P,H = 349.4 Hz], and nonidentified species was observed. Significant improvement was achieved by increasing the stoichiometry of phosgene to 3 equiv, which led to a higher content of the desired phosphane 3a in the reaction mixture.…”

“…For example, 3a possesses a value inbetween those of the dichlorophosphane 1a and the corresponding benzoylphosphane complex [δ ( 31 P) = 113.8 ppm, 1 J P,W = 267.0 Hz] [12] in which the phenyl group is bonded to the carbonyl carbon instead of chlorine. In the 13 C NMR spectra signals of carbonyl carbon atoms of chloroformyl moieties for 3a and 3c were observed as a singlet (at -60 °C) and as a doublet [ 1 J(C,P) = 13.6 Hz; 25 °C] at 176.9 ppm, respectively. The IR absorption bands of these carbonyl groups were observed at 1772 cm -1 (3a) and 1747 cm -1 (3c).…”

Synthesis and structure of {{amino(triorganosilyl)carbene}pentacarbonyltungsten(0)} complexes and attempted synthesis of {[2-bis(trimethylsilyl)methyl-3-triorganosilyl-2H-azaphosphirene-κP]pentacarbonyltungsten(0)}

“…petrolether, toluene) the reaction took more than a week for completion, whereas in polar solvents such as dichloromethane, tetrahydrofuran, 1,2-dimethoxyethane, dimethylformamide the starting material was consumed after 3 h. Apart from different reaction times, the formed products were always identical and could be easily identified by their 31 P NMR data. The major product was the diphosphirane 4 [18] (90%); the diphosphene 5 [19] (3%), the cyclotriphosphane 6 [20] (5%) and the chlorophosphane complex 7 [21] (2%) were all formed as by-products (see Scheme 3 below). I was in accordance with these observations that no evidence for the formation of a 2H-azaphosphirene complex could be obtained.…”

“…The reaction was stirred at different temperatures (0 C, 25 C or 50 C) and monitored by 31 P NMR spectroscopy. The products could easily be identified via comparison with data known from the literature: 31 P NMR: 4 (diphosphirane) À22.6 (d), À122.9 (d) 1 J P,P ¼ 239.0 Hz [18]; 5 (diphosphene) [19]; 6 (cyclotriphosphane) À126.7, À150.9 1 J P,P ¼ 202.8 Hz [20]; 7 (chlorophosphane complex) 52.9 (d sat , 1 J W,P ¼ 268.3 Hz, 1 J P,H ¼ 349.5 Hz) [21]; 8a 27.6 (dd, 1 …”