Group IV heteroadamantanes: synthesis of Si6Sn4and site-selective derivatization of Si6Ge4

Koestler, Benedikt; Gilmer, Jannik; Bolte, Michael; Вировец, А. В.; Lerner, Hans‐Wolfram; Albert, Philipp; Fantuzzi, Felipe

doi:10.1039/d2cc06697a

Cited by 5 publications

(17 citation statements)

References 52 publications

(52 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…12 Exhaustive methylation of this product led to germasilaadamantane 5 (Scheme 2). 36 Subjecting compound 5 to the rearrangement conditions (Ph 3 C[B(C 6 F 5 ) 4 ]/toluene) led to the clean formation of the adamantane cage product 2 with all germanium atoms shied to the bridgehead positions in 69% isolated yield (Scheme 2).…”

Section: Resultsmentioning

confidence: 99%

Selective synthesis of germasila-adamantanes through germanium–silicon shift processes

et al. 2023

Self Cite

View full text Add to dashboard Cite

show abstract

Section: Resultsmentioning

confidence: 99%

Selective synthesis of germasila-adamantanes through germanium–silicon shift processes

et al. 2023

Self Cite

View full text Add to dashboard Cite

show abstract

“…The discovery of the siladodecahedrane [ n Bu 4 N][Cl@Si 20 (SiCl 3 ) 12 Cl 8 ] ([ n Bu 4 N][ 1 ]; Figure ) in 2015 provided the first preparative access to the class of compounds known as silafulleranes, which had already received much attention from the theoretical chemistry community. − [ n Bu 4 N][ 1 ] is straightforwardly available from Si 2 Cl 6 , [ n Bu 4 N]Cl, and n Bu 3 N in one step and in about 30% yield. , The anion [ 1 ] − consists of a dodecahedral Si 20 core carrying 12 SiCl 3 groups and 8 Cl atoms in a perfectly T h -symmetric pattern and hosting a Cl – ion as endohedral guest. This Cl – ion likely plays a crucial role as a structure-directing template during the assembly of the silafullerane cluster before it is eventually encapsulated into it.…”

Section: Introductionmentioning

confidence: 99%

Regioselective Derivatization of Silylated [20]Silafulleranes

et al. 2023

Self Cite

View full text Add to dashboard Cite

Silafulleranes with endohedral Cl − ions are a unique, scarcely explored class of structurally well-defined silicon clusters and host-guest complexes. Herein, we report regioselective derivatization reactions on the siladodecahedrane [nBu 4 N][Cl@ Si 20 (SiCl 3 ) 12 Cl 8 ] ([nBu 4 N][1]), which has its cluster surface decorated with 12 SiCl 3 and 8 Cl substituents in perfect T h symmetry. The room-temperature reaction of [nBu 4 N][1] with excess iBu 2 AlH in ortho-difluorobenzene (oDFB) furnishes perhydrogenated [nBu 4 N][Cl@Si 20 (SiH 3 ) 12 H 8 ] ([nBu 4 N][2]) in 50% yield; the non-pyrophoric [2] − is the largest structurally authenticated (by X-ray diffraction) hydridosilane known to date. A simple switch from pure oDFB to an oDFB/Et 2 O solvent mixture suppresses core hydrogenation and results in the formation of [nBu 4 N][Cl@Si 20 (SiH 3 ) 12 Cl 8 ] ([nBu 4 N][3]). In addition to the exhaustive Cl/H exchange at all 44 Si−Cl bonds of [1] − and the regioselective 36-fold silyl group hydrogenation, we achieved the simultaneous introduction of Me substituents at all 8 SiCl vertices along with the conversion of all 12 SiCl 3 to SiH 3 groups by treating [nBu 4 N][1] with Me 2 AlH/Me 3 Al in oDFB ([nBu 4 N][Cl@ Si 20 (SiH 3 ) 12 Me 8 ], [nBu 4 N][4]; 73%). Quantum-chemical free-energy calculations find an S N 2-Si-type hydrogenation of the exohedral SiCl 3 moieties in [1] − (trigonal-bipyramidal intermediate) slightly preferred over metathesis-like S N i-Si substitutions (four-membered transition state). Cage hydrogenation likely occurs via S N i-Si processes. The experimentally demonstrated influence of an Et 2 O co-solvent, which drastically increases the respective reaction barriers, is attributed to the increased stability of the resulting iBu 2 AlH-OEt 2 adduct and its higher steric bulk compared to free iBu 2 AlH.

show abstract

“…(Left) Prior art in the synthesis of sila-adamantane and SiGe adamantanes, adapted with permission from refs and ). (Right) Overview of the present work.…”

Section: Introductionmentioning

confidence: 99%

“…Wagner and co-workers recently described onepot syntheses of SiGe and SiSn adamantanes (B, Figure 1) through chloride-induced disproportionation reactions where the heavy tetrels occupy the 2°core positions. 34,35 We were interested in exploring whether we could instead introduce Ge atoms at the 4°position of the sila-adamantyl core (Figure 1). In this paper, we describe two related yet distinct approaches that use skeletal isomerization to achieve 4°Ge doping in silicon−germanium heteroadamantanes: (1) single-atom skeletal editing that converts the all-silicon adamantane to a single Ge-doped sila-adamantane, and (2) rational design of strained precursors that contain specific Si x Ge y stoichiometries.…”

Section: ■ Introductionmentioning

confidence: 99%

“…Our interests in studying quantum transport in molecular analogs of silicon semiconductors have motivated us to explore synthetic strategies for controlling Si-diamondoid structures. − While core substitution in heteroadamantanes with Si 4 Q 6 (Q = chalcogenide or pnictogen atom) compositions are well-precedented, − the synthesis of all-tetrel heteroadamantanes has been less developed. Wagner and co-workers recently described one-pot syntheses of SiGe and SiSn adamantanes ( B , Figure ) through chloride-induced disproportionation reactions where the heavy tetrels occupy the 2° core positions. , We were interested in exploring whether we could instead introduce Ge atoms at the 4° position of the sila-adamantyl core (Figure ).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Installing Quaternary Germanium Centers in Sila-Diamondoid Cores via Skeletal Isomerization

Imex Aguirre Cardenas,

Siu,

Pimentel

et al. 2023

J. Am. Chem. Soc.

View full text Add to dashboard Cite

This manuscript describes skeletal isomerization strategies to install one to four quaternary germanium atoms in the sila-adamantane core, in a cluster analogy to precision germanium doping in silicon–germanium alloys. The first strategy embodies an inorganic variant of single-atom skeletal editing, where we use a sila-Wagner-Meerwein bond shift cascade to exchange a peripheral Ge atom with a core Si atom. We can install up to four Ge atoms at the quaternary diamondoid centers based on controlling the Si x Ge y stoichiometry of our precursor. We find that bridgehead Ge centers can be selectively functionalized over bridgehead Si centers in SiGe adamantanes; we use this chemistry in conjunction with scanning tunneling microscopy break-junction (STM-BJ) measurements to show that Si8Ge2 adamantane wires give a 60% increase in single-molecule conductance compared with Si10 adamantanes. These studies describe the first quantum transport measurements in sila-diamondoid structures, and demonstrate how main-chain Ge doping can be used to increase electronic transmission in sila-diamondoid-based molecular wires.

show abstract

Group IV heteroadamantanes: synthesis of Si₆Sn₄and site-selective derivatization of Si₆Ge₄

Abstract: The mixed heteroadamantanes Si6Ge4 and Si6Sn4 are readily accessible from Me2ECl2/Si2Cl6/cat. Cl– (4 × EMe2, 2 × SiCl2, 4 × Si–SiCl3 vertices; E = Ge, Sn). Different from Si6Ge4, two...

Cited by 5 publications

References 52 publications

Selective synthesis of germasila-adamantanes through germanium–silicon shift processes

Selective synthesis of germasila-adamantanes through germanium–silicon shift processes

Regioselective Derivatization of Silylated [20]Silafulleranes

Installing Quaternary Germanium Centers in Sila-Diamondoid Cores via Skeletal Isomerization

Contact Info

Product

Resources

About