Insights into Formation and Relationship of Multimetallic Clusters: On the Way toward Bi-Rich Nanostructures

Abstract

Bismuth-rich polyanions show a unique potential in constructing nanostructured bismuth-based materials, but they are still poorly investigated. We use a ternary precursor of the nominal composition "K 5 Ga 2 Bi 4 " for the formation of [K(crypt-222)] + salts of novel Bi-rich polyanions [Bi@Ga 8 (Bi 2 ) 6 ] q− (q = 3, 5; in 1), (Ga 2 Bi 16 ) 4− (in 2), and [{Ru(cod)} 4 Bi 18 ] 4− (in 3). Their bismuth contents exceed that of the largest homoatomic polyanion, Bi 11 3− . The numbers of bismuth atoms in the anions in 2 and 3 furthermore surmount that of the Bi-richest binary main-group anion, (Ge 4 Bi 14 ) 4− , and they equal (2) or surmount (3) that reported for the anion and the cations with the largest number of Bi atoms so far, [K 2 Zn 20 Bi 16 ] 6− , [(Bi 8 )Ru(Bi 8 )] 6+ , and [(Bi 8 )Au(Bi 8 )] 5+ . Compounds 1 and 2 were obtained from reaction mixtures that contain [La(C 5 Me 4 H) 3 ], apparently assisting in the network formation without being included in the products. In the presence of [Ru(cod)(H 2 CC(Me)CH 2 ) 2 ], yet another reaction pathway leads to the formation of the anions in 3 (conformers 3a and 3b), which are Bi−Bi linked dimers of two "[{Ru(cod)} 2 Bi 9 ] 2− " subunits. They comprise the largest connected assemblies of Bi atoms within one molecule and may be viewed as snapshots on the way toward even larger polybismuthide units and, ultimately, new bismuth modifications. Mass spectrometry allowed insight into the processes in solution that precede the cluster formation. In-depth quantum chemical studies were applied to explain structural peculiarities, stabilities of the observed isomers, and bonding characteristics of these bismuth-rich nanoarchitectures. The work demonstrates the high potential of the method for the access of new Bi-based materials.

Reactive Solubilization of Heterometallic Clusters by Treatment of (TrBi3)2− Anions (Tr=Ga, In, Tl) with [Mn{N(SiMe3)2}2]

“…Cl, for instance. [19,31,24] We were interested to get insight into the bonding situations of the anions in compounds 1 and 2. For this, density functional theory (DFT) calculations [32] were carried out with the TPSSh functional [33] and def2-TZVP basis sets.…”

“…Consequently, only few clusters have so far been reported, in which Ga or In and Bi coexist, such as [Sm@Ga 3− x H 3−2 x Bi 10+ x ] 3− ( x =0, 1) [28] or {[La@In 2 Bi 11 ] 2 Bi 2 } 6− , [29] while there are several examples for the TlBi‐elemental combination. These were reported as salts of binary anions, like [K(crypt‐222)] 2 ‐(TlBi 3 ), [K(crypt‐222)] 3 (Tl 4 Bi 5 ), and [K(crypt‐222)] 3 ‐(Tl 4 Bi 3 ), [30] or as salts of ternary clusters like [{Ru(cod)} 4 Bi 18 ] 4− , [U@Bi 12 ] 3− , [Th@Bi 12 ] 4− , [{Ru(cod)}Tl 2 Bi 6 ] 2− , [U@Tl 2 Bi 11 ] 3− , or [Th@Tl 2 Bi 11 ] 3− , which were obtained from reactions of (TlBi 3 ) 2− with d‐block or f‐block metal compounds [Ru(cod){H 2 CC(Me)CH 2 } 2 ], [UCp # 3 ] or [ThCp # 3 ]Cl, for instance [19, 31, 24] …”

Between Elemental Match and Mismatch: From K12Ge3.5Sb6 to Salts of (Ge2Sb2)2−, (Ge4Sb12)4−, and (Ge4Sb14)4−

“…The anion in compound 3 exhibits a yet unknown molecular structure, which is related, yet not identical to those reported for (Ge 4 Bi 14 ) 4À or (Ga 2 Bi 16 ) 4À . [4,6] The molecular architecture and the bonding situation of the anion in 3 will be discussed in comparison with the corresponding properties of the structurally related anion in 4 below.…”

Capture the missing: formation of (PbBi3)− and {[AuPb5Bi3]2}4− via atom exchange or reorganization of the pseudo‐tetrahedral Zintl anion (Pb2Bi2)2−

“…Consequently, a series of intermetalloid or heterometallic clusters were reported, such as [U@Pb 7 Bi 7 ] 3− , [Th@Bi 12 ] 4− , [Bi@Ga 8 (Bi 2 ) 6 ] q− (q = 3, 5), and [(Bi 6 )Zn 3 (TlBi 5 )] 4− . [22][23][24][25] On the other hand, reactions with softer Lewis acids like the Au(I) cation, (Tt 2 Pn 2 ) 2− anions can also stay intact in the resulting complexes [Au{η 2 -(Tt 2 Pn 2 )} 2 ] 3− (Tt/Pn = Sn/Sb, Sn/Bi, and Pb/Bi). 1,26,27 To understand the limits of such decisions pro-or contradeconstruction of the tetrahedral units, it is essential to further explore these heavy atom anions in the context of atom exchange, fragmentation, and reorganization reactions.…”

“…In contrast, the heavier analogs of (Ge 2 Pn 2 ) 2− , such as (Tt 2 Pn 2 ) 2− (Tt = Sn/Pb, Pn = Sb/Bi) and (TrBi 3 ) 2− (Tr = Ga, In, Tl), tend to undergo fragmentation and reorganization upon interaction with Lewis‐acidic d‐/f‐block compounds. Consequently, a series of intermetalloid or heterometallic clusters were reported, such as [U@Pb 7 Bi 7 ] 3− , [Th@Bi 12 ] 4− , [Bi@Ga 8 (Bi 2 ) 6 ] q − ( q = 3, 5), and [(Bi 6 )Zn 3 (TlBi 5 )] 4− 22–25 . On the other hand, reactions with softer Lewis acids like the Au(I) cation, (Tt 2 Pn 2 ) 2− anions can also stay intact in the resulting complexes [Au{η 2 ‐(Tt 2 Pn 2 )} 2 ] 3− (Tt/Pn = Sn/Sb, Sn/Bi, and Pb/Bi) 1,26,27 …”