Reductive dehydrocoupling of diphenyltin dihydride with LiAlH₄: selective synthesis and structures of the first bicyclo[2.2.1]heptastannane-1,4-diide and bicyclo[2.2.2]octastannane-1,4-diide

Abstract

The reaction of diphenyltin dihydride with LiAlH4 gives access to a set of charged tin cages as their lithium salts.

Molecular Main Group Metal Hydrides

“…Since 2001, various new alkyl- and aryl-substituted alanes (R n AlH 3– n ) and aluminates [R n AlH 4– n ] − have been prepared according to previously established synthetic protocols. − From a reactivity standpoint, these organoaluminum hydrides are known to effect the hydroalumination of unsaturated substrates (e.g., alkenes, alkynes, phosphalkenes), which is a long-established reaction type , that has been used to prepare new Al–H bond-containing molecules. − A new reactivity pathway that has emerged involving carbon-supported aluminum hydrides is centered around the use of aluminum-based Lewis acids in Frustrated Lewis Pair (FLP) chemistry. , …”

“… Single crystal X-ray crystallographic analysis of 1045 shows the shortest Ti–Sn bond length [2.5644(7) Å] reported thus far in the literature, consistent with a significant Ti–Sn π-interaction involving the hydride-free Ti=SnAr iPr6 unit in 1045 (also corroborated by DFT computations) . While perhaps somewhat tangential to the current topic, combining Ph 2 SnH 2 with Li­[AlH 4 ] in varying ratios from 1:2 to 8:1 gave a library of interesting tin clusters via dehydrogenative coupling, such as [Sn 7 Ph 10 ] − , [Sn 8 Ph 12 ] 2– and [Sn 8 Ph 13 ] − …”

Structure and Bonding in a Diamond‐Shaped Tin Cluster Possessing a cyclo‐Sn4 Core

“…The distorted cubic cluster[ DMPSn] 4 Sn 4 (DMP = 2,6-dimesitylphenyl) is one such example, [3] produced by the reductiono f [ DMPSnCl] in the presence of excess K. Other examples include pentagonal bipyramidal [ Dipp 2 ArSn] 2 [cyclo-Sn 5 ], [4] the tricapped trigonal prism Sn 9 Ar Trip 2 3 , [5] and as tructural isomer of hexastannaben-zene, [(Trip) 2 Sn[(Trip)Sn] 2 Sn 2 Sn(Trip 2 )] [6] (Trip = 2,4,6-triisopropylphenyl), among others. [7][8][9][10][11] To date, there is no reported route to access as imple Sn cluster of the formula [RSn] 4 ,d espite efforts to preparet his speciesd ating back to 2001. [3] More generally,t he possibility of an [RSn] 4 species has raised interest and speculation of ag roup 14 cluster with at etrahedrane core, but theoretical calculations strongly indicatet hat tetranuclear clusters of this type should possessamoreo pen, 4-membered ring structure.…”