Synthesis, Structure, Dynamics, and Selective Methylation of Platinum and Palladium Diphosphametallacyclobutane Complexes

Abstract

Additional Information on Synthesis of IsHP(BH 3 )CH 2 PHIs(BH 3 ) (1-BH 3 )As mentioned in the experimental section, use of a slight excess of IsMgBr (2.4 equiv) ensured complete 1,2diarylation of Cl 2 PCH 2 PCl 2 , but subsequent formation of IsH during the workup hindered crystallization of 1-BH 3 . In that case (starting with 2.24 g (10.3 mmol) of Cl 2 PCH 2 PCl 2 ), the following procedure was used to obtain the product as a solid.Removal of the solvent from crude 1-BH 3 (formed on addition of BH 3 -THF to crude 1) gave an oily mass. 31 P NMR analysis showed two peaks corresponding to the diastereomers of the diphosphine diborane (δ -31.8, -33.9, 1:1). The mass was diluted with ca. 100 mL of pentane and allowed to stand for one week. A white precipitate (106 mg) was collected by filtration. 31 P NMR analysis of both the solid and solution showed the presence of 1-BH 3 and minor impurities. After removing the solvent from the solution, the oily mass was dissolved in 5 mL of pentane and then the solvent was removed under reduced pressure. This process was repeated until the oily mass took on a chalky appearance and was no longer translucent. At this point the mass was redissolved in 5 mL of pentane and a small amount of white precipitate appeared. The slurry was passed through a 0.5 x 2.0 cm Celite pipet column, which collected the white precipitate while the brown solution passed through. The column was washed with 5 mL more pentane and the pentane washings were collected -some of the white solid seemed to dissolve with this wash. Finally the Celite column was washed with 5 mL of Et 2 O, which was then removed in vacuo to afford 0.185 g of a white solid. A sample of 5 mg of the white solid was dissolved in 0.7 mL of Et 2 O, and 31 P NMR analysis of the material showed two peaks corresponding to the two diastereomers of the diphosphine diborane (δ -32.1 (minor), -33.9 (major), 1:10) and a minor species corresponding to a diphosphine monoborane (δ -29.5, -103.3 (< 5%)). After 24 h, this sample had reverted to a spectrum very similar in appearance to the original reaction solution, now with a 7:10 ratio of diastereomers. The pentane was removed S7 from the washings in vacuo and the above protocol (addition/removal of pentane followed by a Celite column) was repeated to afford another 0.554 g of a white solid (0.739 g total (1.44 mmol, 14.0% yield from Cl 2 PCH 2 PCl 2 )). Further repetitions proved unfruitful. Additional Information on Synthesis of rac-and meso-MiniPhos 5, IsMePCH 2 PMeIsPt-Catalyzed Synthesis of MiniPhos 5: Background Reactions Coupling of PHMeIs and CH 2 I 2 in the presence of NaOSiMe 3 but without a Pt catalyst was monitored by 31 P NMR spectroscopy for 96 h. After this time, signals were identified at δ -53.4 (1%), -53.9 (<1%), -56.6 (<1%), -61.4 (<1%), -107.4 (<1%). The low conversion without the catalyst suggests that the background is not significant in the catalytic reaction. Similarly, the reaction of MeI with IsHPCH 2 PHIs (1) and NaOSiMe 3 in the absence of a Pt catalyst was monitored...

Synthesis, structure, and luminescence of the “octahedral” cluster Cu4I4(rac-IsMePCH2PMeIs)2 (Is=2,4,6-(i-Pr)3C6H2)

“…Mass spectrometry was performed at the University of Illinois. Commercial CuI and rac-IsMePCH 2 PMeIs, prepared by the literature method [11], were used.…”

“…This behavior was rationalized by considering the shortened Cu-Cu distances in the 3 CC excited state, requiring distortion of the bridging ligand geometry, which would be limited by bulky substituents [2]. To investigate similar effects with P$P donors B, we report here study of a Cu 4 I 4 octahedral cluster containing the bis(phosphine) rac-IsMePCH 2 PMeIs, which contains very bulky ''isityl'' (Is = 2,4,6-(i-Pr) 3 C 6 H 2 ) groups [11].…”

Structures of Pt(0)P3, Pt(0)P4 and Pt(II)P4 – Distortion isomers

“…In three of these one isomer is triclinic and one monoclinic (Albano et al, 1966;Chaloner et al, 1989;Engelhardt et al, 1984;Ferguson et al, 1993;Powell et al, 1995). In one example one is tetragonal and the other monoclinic (Chapp et al, 2012).…”

“…The mean values of Pt-P bond distances are 2.334 and 2.328 Å, respectively. Two dissimilar bidentate ligands in tetragonal, meso-, and triclinic rac-[Pt{η 2 -(Me)(C 15 H 23 )P*(CH 2 )P*(C 15 H 23 ) (Me)}{η 2 -Ph 2 P(CH 2 ) 2 PPh 2 }]⋅2(CF 3 SO 3 ) (Chapp et al, 2012) build up a distorted square-planar geometry about Pt(II) atoms. One of the bidentate ligand forms four-(P*CP*) and another one forms five-(PC 2 P) membered metallocyclic rings with the values of P-Pt-P angles of 73.2° and 83.6° in tetragonal isomer and 72.1° and 83.7° in triclinic.…”

“…ligands, one which creates four-(P*CP*) and another one five-(PC 2 P) membered metallocycles (Chapp et al, 2012). The mean Pt-P* and Pt-P bond distances are 2.350 and 2.332 Å and the values of the respective angles are 72.6° (P*CP*) and 83.6° (PC 2 P).…”