Dinuclear Chlorotetrylenes of Silicon, Germanium, and Tin Based on a Backbone‐Bridged Bis(amidine)

Abstract

Dedicated to Matthias Driess on the occasion of his 60 th birthdayBis(chlorotetrylene)s of Si, Ge, and Sn have been synthetically realized starting from the backbone-bridged bis(amidine) 1. Double deprotonation of 1 and subsequent reaction with trichlorosilane affords the bis(dichorosilane) 2, which is converted to the respective bis(chlorosilylene) 3 by dehydrochlorination using lithium bis(trimethylsilyl)amide. The related bis(chlorogermylene) 4 and the bis(chlorostannylene) 5 are obtained by reacting the dilithium salt with GeCl 2 • (dioxane) and SnCl 2 , respectively. 2 readily reacts with benzil affording the bis(siladioxolene) 6, while no reaction was observed when using the bis(chlorogermylene) 4. The complexes have been fully characterized and their molecular solid-state structures have been investigated by means of single-crystal X-ray diffraction analysis.

Polydentate Amidinato‐Silylenes, ‐Germylenes and ‐Stannylenes

“…Compounds of this type have two or three AT fragments connected to a spacer through their amidinate central C atom (D also contains one or two AT groups) (Figure 17). [48][49][50][51] The syntheses of ATs AG-AL (Figure 17) require the attachment of two or three C-bonded amidinate fragments to the corresponding spacer prior to the final reaction with the appropriate tetrel atom precursor. Two different approaches have been used.…”

Synthesis, Characterization, and Reaction of Digermylenes

“…1 H NMR (400 MHz, C 6 D 6 , 298 K, ppm): δ 9.02 (s, 1H, Ph-H), 8.25 (m, 2H, Ph-H), 7.00 (s, 1H, Ph-H), 6.83-6.98 (m, 12H, Ar-H), 4.92 (s, 2H, γ-CH), 3.45 (sept, J = 6.6 Hz, 4H, CHMe 2 ), 2.96 (sept, J = 13.6, 6.8 Hz, 4H, CHMe 2 ), 1.40 (s, 12H, CMe), 0.95-0.99 (m, 36H, CHMe 2 ), 0.84 (d, J = 6.8 Hz, 12H, CHMe 2 ). 13 (8). A solution of 1,3-C 6 H 4 (OGeL) 2 (0.545 g, 0.5 mmol) and sulfur (0.032 g, 1 mmol) in toluene (40 mL) was stirred at 85 °C for 12 hours.…”

“…One representative example is the digermylene oxide with the oxygen atom connecting the two Ge(II) centers [5] . Greater spacing distances between two Ge(II) sites have been achieved by using p ‐benzenenediamido, [6] p ‐phenylene, p ‐biphenylene, [7] p ‐terphenylene, [8] cyclohexylene, [9] or flexible alkyl chains [10] linkers in specially designed ligands. Intriguingly, the elimination of HCl from the β ‐diketiminate ligand supported germylene chloride LGeCl (L=CH[C(Me)NAr] 2 , Ar=2,6‐ i Pr 2 C 6 H 3 ) [11] gave a heterofulvene‐like germylene L′Ge (L′=HC[(C−CH 2 )CMe](NAr) 2 ) (Scheme 1), [12] which unexpectedly produced digermylenes by reactions with dibromoethane, [12] HN(SiMe 3 ) 2 , [13] PhC(N t Bu) 2 GeCl, [14] or (HO) 2 BPh [15] .…”

Amidinatotetrylenes Donor Functionalized on Both N Atoms: Structures and Coordination Chemistry

“…In this regard, the metal complexes that are equipped with polydentate ATs have been generally prepared from metal-free ATs (generically E(R 1 NC(R 2 )NR 1 )X; E = heavier tetrel atom, X = anionic group; see Figure ) functionalized with at least one additional donor group (D). Figure shows the currently known types of metal-free potentially polydentate ATs, − which formally result from (a) attaching a donor fragment to the E atom (X position; type I ), − (b) connecting with a linker, which can also have additional donor or prone to undergo metalation groups, two ATs through their E atoms (X position; type II ), − through the amidinate central C atoms (R 2 position; type III ) − or through one of the two amidinate N atoms (R 1 position; type IV ), and (c) attaching a donor fragment to one of the N atoms (R 1 position; type V ). , By far, types I and II , whose syntheses normally imply an easy Cl replacement with an appropriate lithiated group on well-known chlorido-ATs, are the most explored donor-functionalized ATs, having led to a great variety of metal complexes fitted with κ 2 E , D -, − κ 2 E , E -, , κ 3 E , D , E -, κ 3 E , C , E - ligands, many of them with catalytic applications . On the other hand, the functionalization pathways that lead to types III , IV , and V , which imply modifications on the amidinate skeleton befor...…”