Homoleptic Silver Complexes of the Cages P₄Se₃ and As₄S₃

Abstract

By reacting P 4 Se 3 and As 4 S 3 with Ag[Al(OR F ) 4 ] {-R F = -C(CF 3 ) 3 or -hfip [= -C(H)(CF 3 ) 2 ]} in suitable solvents, (5) were synthesized and characterized by SC-XRD, Mass spectrometry, Raman spectroscopy as well as solution NMR spectroscopy. When using stronger coordinating anions, only P 4 Se 3 forms an isolable complex yielding 1 featuring a [Ag 2 (P 4 Se 3 ) 2 ] 2+ core capped by anions acting as the first example of P 4 Se 3 coordinating through selenium atoms. Upon using the weakly coordinating anion [Al{OC(CF 3 ) 3 } 4 ] -, the dimeric complexes 2 and 4 are accessible in dichloromethane or ortho-difluorobenzene (o-dfb), respectively. Complex 2 shows isolated [Ag 2 (P 4 Se 3 ) 4 - [a] Computational Details: All computations were performed by using the program package TURBOMOLE 7.1. [38] All investigated molecular structures were optimized using the functionals BP86 [39] (with RI approximation [40] ) and together with the basis sets def-SV(P). [41] A fine integration grid (m4) and the default SCF convergence criteria (10 -6 a.u.) were used. The vibrational frequencies of all assessed species were computed with the implemented module AOFORCE [42] and checked for minima (no imaginary frequencies).Preparation of P 4 Se 3 : P 4 Se 3 was obtained by heating stoichiometric amounts of grey selenium and white phosphorus in tetraline followed by extraction and recrystallization in CS 2 , following the literature procedure. [43] FT-Raman: ν = 135 (vw), 214 (m), 317 (sh), 324 (vw), 346 (sh), 365 (vs), 370 (sh), 405 (vw), 484 (w) cm -1 . NMR: 31 P NMR (122 MHz, CS 2 , r.t.): δ = -104.6 [d, 3 P basal , 2 J(P basal , P apical ) = 72 Hz], 37.4 [q, 1 P apical , 2 J(P basal , P apical ) = 72 Hz] ppm. 77 Se (57 MHz, CS 2 , r.t.): δ = 763.3 (m, P 4 77 SeSe 2 ) ppm. 31 P NMR (162 MHz, CD 2 Cl 2 , r.t.): δ = -114.1 [d, 3 P basal , 2 J(P basal , P apical ) = 72 Hz], 30.5 [q, 1 P apical , 2 J(P basal , P apical ) = 72 Hz] ppm. 31 P NMR (162 MHz, SO 2 , r.t.): δ = -113.7 [d, 3 P basal , 2 J(P basal , P apical ) = 72 Hz], 29.6 [q, 1 P apical , 2 J(P basal , P apical ) = 72 Hz] ppm. Mass Spectra: (ASAP, Source Voltage 25 V, Source Offset 25 V, Temperature 400°C, positive): m/z = 173 [P 3 80 Se] + , 365 [HP 4 80 Se 3 ] + .Preparation of As 4 S 3 : As 4 S 3 was obtained by melting stoichiometric amount of the elements for five days at 420°C, followed by Soxhlet-extraction with toluene. FT-Raman: ν = 145 (vw), 172 (w), 186 (m), 207 (m), 217 (m), 230 (sh), 273 (vs), 338 (sh), 359 (m), 375 (vw) cm -1 . Mass Spectra: (ASAP, Source Voltage 25 V, Source Offset 25 V, Temperature 400°C, positive): m/z = 257 [As 3 32 S] + , 289 [As 3 32 S 2 ] + , 321 [As 3 32 S 3 ] + , 396 [As 4 32 S 3 ] + , 397 [HAs 4 32 S 3 ] + , 428 [As 4 32 S 4 ] + , 429 [HAs 4 32 S 4 ] + .

Coordination Chemistry of P4S3 and P4Se3 towards the Iron Fragments [Fe(Cp)(CO)2]+ and [Fe(Cp)(PPh3)(CO)]+

“…[a] P 4 S 3 Raman [12] 1a IR 1a Raman Assignment [b] 3 IR 3 Raman Assignment [b] P 4 Se 3 Raman [14][c]…”

“…The NMR spectra of isolated crystals of complexes 1a, 2,a nd 3 dissolved in CD 2 Cl 2 show that the used [Al(OR F ) 4 ] À anion stays intact over the course of the reactions because only the typical 19 Fa nd 27 Al NMR signals are visible (see the Supporting Information, FiguresS4-S24). Owing to their dynamic nature in solution,t he known silver complexes Ag(P 4 S 3 ) n [WCA] [12,13] and Ag(P 4 Se 3 ) n [WCA] (n = 1, 23 ) [14] show only two distinct signals of the ligandsi nt he 31 PNMR spectra.C omplexes 1 and 2 show three distinct signals of the apical phosphorus atom P a ,t he coordinated basal phosphorus atom P b/coord ,a nd the noncoordi-nated phosphorus atoms P b/noncoord .T his demonstratest hat the P 4 Se 3 and P 4 S 3 cages are firmly bound to the Fp moiety through one of their basal phosphorusa toms, similart ot he more electron-rich analogues [Cp*Ru(L 2 )(P 4 S 3 )] + and [Cp*Ru(L 2 )(P 4 Se 3 )] + (L 2 = bidentate phosphine) but unlike the more weakly bound P 4 ligand in [FpÀP 4 ] + . [3,10] Complex 3 shows five different phosphorus signals, one for the PPh 3 ligand and four fort he P 4 S 3 cage.…”

“…The shift of P b/coord is stronger in the examples with bisphosphine ligands. In contrastt oc omplexes 1, 2,a nd 3,w hich are firmly bound at room temperature, the recently synthesized complex [FpÀP 4 ] + [Al(OR F ) 4 ] À shows fluctuating behavior at room temperature that can be frozen out at temperatures below 263 K. [10] The 77 Se spectra (see the Supporting Information, Figure S16) of complex 2 showst hat the multiplet of the P 4 Se 3 cages in Ag(P 4 Se 3 ) n [Al(OR F ) 4 ], whichc an be found at d % 800 ppm, [14] splits into two distinct signals at d = 775 and 622 ppm, with the high-field shifteds ignal at d = 622 ppm Figure 2. 31 PNMR spectra of complexes 1, 2,a nd 3 as wellast he free ligands P 4 S 3 and P 4 Se 3 in CD 2 Cl 2 at room temperature.…”

“…Generally,t he experimentalR amans pectra are in good agreement with the calculated spectra (see the Supporting Information, Figures S1-S3) that wereu sed for further evaluation and band assignment. [13] and [14] are given.…”

“…[10] Yet, quite an umber of complexes of weak and often poorly soluble ligandsw ith the silver ion of Ag[Al(OR F ) 4 ]a re accessible;t hat is, those with inorganic rings, such as S 8 ,S e n (n = 6, 12), and the cages P 4 ,P 4 S 3 ,P 4 Se 3 ,A s 4 S 3 ,a nd As 4 S 4 . [11,[12][13][14] Hence, the concept of ligand-transfer chemistry can be tested by reactinge asily accessible representatives of thesec ompounds with suitable, soluble transition-metal halides. Herein, we present complexes of P 4…”