Synthesis and Characterization of Methylzinc Tri(tert‐butyl)silylphosphanide as well as Related Sodium and Potassium Phosphanylzincates

Abstract

The reaction of dimethylzinc and tri(tert-butyl)silylphosphane in toluene yielded dimeric methylzinc tri(tert-butyl)silylphosphanide (1) which crystallized tetrameric. Compound 1 was deprotonated with sodium in DME and the solvent-separated dimeric ion pair [(dme) 3 Na] ϩ [(dme)Na(MeZn) 2 (μ-PSitBu 3 ) 2 ] Ϫ (2) was isolated. The reaction of 1 in THF with two equivalents of potassium and one equivalent of tri(tert-butyl)silylphosphane gave dimeric [{tBu 3 Si(H)P}{(thf) 2 K} 2 (MeZn)(PSitBu 3 )] 2 (3). Both of these phos-3087 phanylzincates contain Zn 2 P 2 cycles with Zn-P bond lengths of approximately 237 pm, whereas in 1 larger Zn-P bond lengths of 248.5 pm were found due to the larger coordination numbers of the phosphorus and zinc atoms.

Recent developments in the field of organic heterobimetallic compounds of the alkaline-earth metals

“…Surprisingly, dimeric methylzinc tri(tert-butyl)silylphosphanide crystallizes as a tetrameric molecule, however, in solution it dissociates into the dimer again. 85 The reaction of this compound with alkaline-earth metals yielded the corresponding 1,3-dialkyl-2,4-bis{tri(tert-butyl)silyl}-1,3-dizinca-2,4-diphosphetane-2,4-diides by deprotonation of the phosphanide units with a similar molecular structure as shown in Fig. 6.…”

Ternary synthesis of colloidal Zn3P2quantum dots

“…This intermediate was also implicated as the species directly responsible for the formation of QDs in a typical heat-up synthesis. This intermediate was the only molecular species containing phosphorus observed by 31 P{ 1 H} NMR in an aliquot taken 30 seconds post injection from a typical synthesis (Fig. S11, ESI †) and no phosphorus containing molecular species were observed by 31 P{ 1 H} NMR in an aliquot taken after Zn 3 P 2 QD formation.…”

“…This intermediate was the only molecular species containing phosphorus observed by 31 P{ 1 H} NMR in an aliquot taken 30 seconds post injection from a typical synthesis (Fig. S11, ESI †) and no phosphorus containing molecular species were observed by 31 P{ 1 H} NMR in an aliquot taken after Zn 3 P 2 QD formation. These observations indicate the loss of this intermediate by 31 P{ 1 H} NMR directly correlates with the formation of QDs and is not a by-product of the reaction.…”

“…There is literature precedent for related tetrahedrally-coordinated phosphorus species displaying 31 P{ 1 H} NMR signals at À318.5 and À270.3 ppm. 30,31 We were unable to isolate and purify the proposed (Et 2 Zn)P(ZnAc) 2 (SiMe 3 ) species due to its limited lifetime and instability under reduced pressure. This intermediate was also implicated as the species directly responsible for the formation of QDs in a typical heat-up synthesis.…”

“…S11, ESI †) and no phosphorus containing molecular species were observed by 31 P{ 1 H} NMR in an aliquot taken after Zn 3 P 2 QD formation. These observations indicate the loss of this intermediate by 31 P{ 1 H} NMR directly correlates with the formation of QDs and is not a by-product of the reaction. To further support this hypothesis, a QD synthesis was performed in a J-Young tube to monitor the formation and disappearance of the observed molecular intermediate during QD formation.…”