Cyclo‐Dipnictadialanes

Abstract

Using the Al I precursor Cp 3t Al in conjunction with triphosphiranes (PAr) 3 (Ar = Mes,Dip,Tip) we have succeeded in preparing Lewis base-free cyclic diphosphadialanes with both the Al and Patoms bearing three substituents.U sing the sterically more demanding Dip and Tips ubstituents the first 1,2-diphospha-3,4-dialuminacyclobutanes were obtained, whereas with Mes substituents [Cp 3t Al(m-PMes)] 2 is formed. This divergent reactivity was corroborated by DFT studies, which indicated the thermodynamic preference for the 1,2diphospha-3,4-dialuminacyclobutane form for sterically more demanding groups on phosphorus.U sing Cp*Al we could extend this concept to the corresponding cyclic diarsadialanes [Cp*Al(m-AsAr)] 2 (Ar = Dip,T ip) and additionally add the phosphorus variants [Cp*Al(m-PAr)] 2 (P = Mes,D ip,T ip). The reactivity of one variant [Cp 3t Al(m-PPh)] 2 towards NHCs was tested and resulted in double NHC-stabilised [Cp 3t -(IiPr 2 )Al(m-PPh)] 2 .

Generation of a transient base-stabilised arylalumylene for the facile deconstruction of aromatic molecules

“…10 In 2018, our group reported the compound [(η 5 -Cp 3t )Al I ] ( VI , Scheme 1a) (Cp 3t = 1,3,5-tri- tert -butylcyclopentadienyl), a monomeric species that showed several interesting reactivity patterns. 11 We also reported a parent alumylene ( i.e. , Al I H) species ( VII , Scheme 1a) stabilised by two cyclic (alkyl)(amino)carbenes (CAACs) which showed 36% singlet diradical character (Al III ).…”

Cyclische Dipnictadialane

“…Zunächst haben wir die Reaktion von (MesP) 3 mit drei ¾quivalenten Cp 3t Al in C 6 D 6 bei Raumtemperatur untersucht. [28] Dies führte zu einem anfänglichen Farbwechsel zu Orange,und nach einigen Minuten wurde eine gelbe Lçsung erhalten, die ein Signal im 31 [29] Dies wurde durch die anfängliche Addition von ArGa an ein dreigliedriges N 2 Ga-Ringsystem und die anschließende Insertion eines zweiten ArGa erklärt, wodurch [ Dip Te rGaNTol] 2 entsteht. Folglich wurden Diphosphene als potenzielle Zwischenstufen bei der Bildung von 1b und 1c identifiziert.…”

“…1a-c kristallisieren in der triklinen Raumgruppe P1 ¯mit zwei Molekülen in der Elementarzelle (Abbildung 1). [28] 1a befindet sich auf einem kristallografisch induziertem Inversionszentrum, mit einem zentralen Al 2 P 2 -Rechteck mit alternierenden P-und Al-Atomen und P-Al-Abständen von 2.3176(7) bzw. 1) ; [31] (Cp 3t AlBr) 2 [32] 2.586(3) ,( Dip Te rAl) 2 (CSiMe 3 ) 2 [33] 2.4946( 9) ], und annähernd identische P1-Al1-und P2-Al2-Bindungen [1b 2.4057-(9), 2.4090(9) ; 1c 2.4090(5), 2.3977( 5 Um die Bindungssituation dieser unterschiedlichen Phosphor-Aluminium-Heterocyclen zu untersuchen, führten wir DFT-Berechnungen für 1a und 1b auf dem PBE0-D3(BJ)/ def2-SVP-Theorieniveau durch.…”

Cationic dialanes with fluxional π-bridged cyclopentadienyl ligands

“…4,5 This portfolio of bridged dialanes was extended recently by an oxo-bridged anionic dialane with a highly strained Al-Al -bond 6 as well as bis-phosphinidene-bridged dialanes. 7 The reversible insertion of aluminylenes into Al-H bonds is a novel pathway to dialanes 8 and allowed for the synthesis of the only known cationic dialanes. 9 Surprisingly, although cyclopentadienyl-ligands have been fundamentally important for the development of Al(I) complexes like in the first Al(I) compound [(AlCp*) 4 ] (Cp* = C 5 Me 5 ) 10 or in a first Al 4 + cluster salt, 11 only very few examples for Al II -Al II bound structures stabilized with Cp-ligands are known.…”

“…4,5 This portfolio of bridged dialanes was extended recently by an oxo-bridged anionic dialane with a highly strained Al–Al σ-bond 6 as well as bis-phosphinidene-bridged dialanes. 7 The reversible insertion of aluminylenes into Al–H bonds is a novel pathway to dialanes 8 and allows for the synthesis of the only known cationic dialanes. 9…”