Reactivity of Divalent Germanium Alkoxide Complexes Is in Sharp Contrast to the Heavier Tin and Lead Analogues

Abstract

The chemistry of β-diketiminate germanium alkoxide complexes has been examined and shown to be in sharp contrast to its heavier congeners. For instance, (BDI)GeOR (BDI = [{N(2,6-(i)Pr(2)C(6)H(3))C(Me)}(2)CH], R = (i)Pr, (s)Bu, (t)Bu) does not react with carbon dioxide to form a metal carbonate complex. Addition of aliphatic electrophiles, such as methyl iodide or methyl triflate, results in the net oxidative addition to the germanium, giving cationic tetravalent germanium complexes, [(BDI)Ge(Me)OR][X] (X = I, OTf). An examination of the contrasting reactivities of the alkoxide ligand and the germanium loan pair with Lewis acids yielded the unusual germanium(II)-copper(I) adduct, {μ(2)-Cu(2)I(2)}[(BDI)GeO(t)Bu](2). This complex not only displays a rare example of a divalent Ge-Cu bond, but is the first example in which a planar Cu(2)I(2) diamond core possesses a three-coordinate copper bound to another metal center.

N‐Alkoxy Carboxamide Stabilized Tin(II) and Germanium(II) Complexes for Thin‐Film Applications

“…In 5 , the Ge(1)–O(1) and Ge(1)–O(3) bond lengths (Table ) of 2.226(19) and 2.2509(18) Å, respectively, are understandably much longer than previously reported Ge–alkoxide bonds because of their purely coordinative characteristics. The respective Ge(1)–O(2) and Ge(1)–O(4) bond lengths of 1.8931(18) and 1.9086(18) Å are much closer to the reported Ge–O bond lengths in [(L)GeOC(H) 2 (PhOMe‐4)] {L = N(C 6 H 2 [C(H)Ph 2 ] 2 i Pr‐2,6,4)(Si i Pr 3 ), 1.8120(19) Å}, [(BDI)GeO t Bu] {BDI = [N(2,6‐ i Pr 2 C 6 H 3 )C(Me)] 2 CH, 1.8284(3) Å}, and [LGe(O i Pr)(HO i Pr)] [L = amine(triphenolate), 1.799(2) Å] . Similarly, in 10 , the respective Sn(1)–O(1) and Sn(1)–O(3) bond lengths of 2.397(2) and 2.366(2) Å are longer than those of common Sn–alkoxide bonds, whereas the Sn(1)–O(2) [2.110(2) Å] and Sn(1)–O(4) bond lengths [2.099(2) Å] showed similar characteristics to those of previously reported complexes such as (BDI)SnO i Pr, (BDI)SnO t Bu, and [Sn(C 5 H 7 O 2 )(C 2 H 3 O 2 )], which have Sn–O bond lengths of 2.000(5), 2.0179(16), and 2.156(4) Å, respectively.…”

Germylene Cyanide Complex: A Reagent for the Activation of Aldehydes with Catalytic Significance

“…The average GeN bond lengths in these compounds 3 (1.979 Å), 4 (1.961 Å), 5 (1.971 Å), and 6 (1.986 Å) are almost identical to the corresponding bond lengths in germylene monocyanide complex 2 (average: 1.972 Å). The GeO bonds in these compounds ( 3 (1.872(1) Å), 4 (1.946(4) Å), 5 (1.907 Å; average), and 6 (1.875(4) Å)) are longer than the GeO bond (1.8284(3) Å) in Fulton’s germylene alkoxide complex [GeO t Bu(L 2 )] 15c…”

Reactivity of an N,N‐Chelated Germylene Toward Substituted Alkynes, Alkenes, and Allenes

“…In this regard, the groundbreaking achievements have been accomplished by Power et al, who demonstrated that the sterically encumbered germylenes (Ar′) 2 Ge (Ar′ = 2,6‐Ar 2 –C 6 H 3 ; Ar = 2,4,6‐Me 3 –C 6 H 2 or 2,6‐ i Pr‐C 6 H 3 ) activate H 2 and NH 3 ,, and additional examples illustrating their intriguing reactivity followed . A high propensity to react with unsaturated substrates such as alkynes,, alkenes, dienes, carbonyl compounds,, isocyanides represents another typical property of germylenes. As a contribution to this field, we have recently reported the synthesis of an N , N ‐chelated germylene, [( i Pr) 2 NB(N‐2,6‐Me 2 C 6 H 3 ) 2 ]Ge ( 1 ), that exerts the typical, germylene‐like, reactivity toward dienes and alkynes .…”