The thermolysis of Cp'''Ta(CO) 4 with white phosphorus (P 4 ) gives access to [{Cp'''Ta} 2 (μ,η 2 : 2 : 2 : 2 : 1 : 1 -P 8 )] (A), representing the first complex containing a cyclooctatetraene-like (COT) cyclo-P 8 ligand. While ring sizes of n > 6 have remained elusive for cyclo-P n structural motifs, the choice of the transition metal, coligand and reaction conditions allowed the isolation of A. Reactivity investigations reveal its versatile coordination behaviour as well as its redox properties. Oxidation leads to dimerization to afford [{Cp'''Ta} 4 (μ 4 ,η 2 : 2

Dedicated to Professor Sjoerd Harder on the occasion of his 60th birthday.

A missing family of the extremely air sensitive tripentelyltrielanes was discovered. Their stabilisation was achieved by using the bulky NHC IDipp (NHC=N‐heterocyclic carbene, IDipp=1,3‐bis(2,6‐diisopropylphenyl)‐imidazolin‐2‐ylidene). The tripentelylgallanes and tripentelylalanes IDipp ⋅ Ga(PH2)3 (1 a), IDipp ⋅ Ga(AsH2)3 (1 b), IDipp ⋅ Al(PH2)3 (2 a) and IDipp ⋅ Al(AsH2)3 (2 b) were synthesised by salt metathesis of IDipp ⋅ ECl3 (E=Al, Ga, In) with alkali metal pnictogenides such as NaPH2/LiPH2 ⋅ DME and KAsH2, respectively. Moreover, the detection of the first NHC‐stabilised tripentelylindiumane IDipp ⋅ In(PH2)3 (3) was possible by multinuclear NMR spectroscopy. Initial investigations of the coordination ability of these compounds resulted in the successful isolation of the coordination compound [IDipp ⋅ Ga(PH2)2(μ3‐PH2{HgC6F4}3)] (4) by reaction of 1 a with (HgC6F4)3. The compounds were characterised by multinuclear NMR spectroscopy as well as single crystal X‐ray diffraction studies. Supporting computational studies highlight the electronic features of the products.

The ability of phosphacyclohexadienyl anions [Li(1-R-PC 5 Ph 3 H 2 )] [R = Me (1 a), nBu (1 b), tBu (1 c), Ph (1 d) and CH 2 SiMe 3 (1 e)] to initiate hydrofunctionalisation reactions was investigated and compared with simple, commercially available compounds, such as LiOtBu, KOtBu and nBuLi. All compounds are expedient catalysts for the hydroboration of a wide scope of substrates, ranging from aldehydes to imines and esters. In the hydroboration of carbon dioxide, however, only our system was observed to efficiently produce the desired methanol equivalents.

am Main Max-von-Laue-Straße 7, 60438 Frankfurt am Main (Deutschland) © 2023 Die Autoren. Angewandte Chemie veröffentlicht von Wiley-VCH GmbH. Dieser Open Access Beitrag steht unter den Bedingungen der Creative Commons Attribution Non-Commercial NoDerivs License, die eine Nutzung und Verbreitung in allen Medien gestattet, sofern der ursprüngliche Beitrag ordnungsgemäß zitiert und nicht für kommerzielle Zwecke genutzt wird und keine Änderungen und Anpassungen vorgenommen werden. Schema 1. a) Bekannte cyclo-(PR) n (I, R = Alkyl oder Aryl) und cyclo-P n -Strukturmotive für n = 3-6 (II-V), b) ausgewählte P 8 -Spezies (VI-VII, {L n M} = {Cp* 2 Sm}, {( dmp nacnac)Fe} ( dmp nacnac = [{N(C 6 H 3 Me 2 -2,6)C-(Me)} 2 CH] À ), {(1,1'-Fc(NSi t BuMe 2 ) 2 )Sc}) und kronenförmige cyclo-E 8 8À enthaltende Verbindungen (VIII, E = As, Sb, M = Cr, Mo, Nb, Ta), c) Synthese von [{Cp'''Ta} 2 (μ,η 2 : 2 : 2 : 2 : 1 : 1 -P 8 )] (A).