Echte Chemie: Spektroskopische und kristallographische Analysen bestätigen die chemische Reaktion von CO2 mit Carbenen in flüssigen 1,3‐Dialkylimidazoliumacetaten sowie die unterstützende Rolle des Acetations in diesen Reaktionen. Wenn CO2 durch [C2mim][OAc] geleitet wurde, konnte die Bildung des entsprechenden Imidazoliumcarboxylats, [C2mim+‐COO−], beobachtet werden.

Polymeric metal–organic nanocapsule networks (polyMONCs), where metal–organic nanocapsules (MONCs) are connected by functional polymers, could possess the properties of traditional polymers and also retain the structures of MONCs. In this work, we constructed novel polyMONCs based on Mg-seamed pyrogallol[4]­arene-containing MONCs through supramolecular coordination-driven self-assembly. The MONCs can be successfully polymerized using poly­(ethylene glycol) as the linker, and the prepared polyMONCs can be further made into gels with self-healing properties and stimuli responsiveness. Advantageously, single crystals of MONCs cross-linked by ethylene glycol/diethylene glycol were obtained, giving us direct perspectives to mimic and investigate the self-assembly process of polyMONCs.

Carbon dioxide functionalization is a potentially transformative method to enhance the sustainability of carbon-based commercial chemicals. The reductive functionalization of CO2 via C–C bond forming reactions is one route to deriving structurally diverse products from this renewable resource. Despite considerable advances in catalytic CO2 reduction into smaller molecular fragments, such as CO, there remains relatively few transition metal mediated processes to elaborate CO2 via reductive C–C bond functionalization. An investigation of iron(0) complexes capable of reductive coupling with CO2 to generate acrylate and oxalate are described here. A set of [(depe)2Fe] (depe = 1,2-bis­(diethylphosphino)­ethane) complexes were found to reductively functionalize CO2 with ethylene or a second molecule of CO2 to afford C3 and C2 products, respectively. Several factors influencing the stoichiometric yield of these transformations were examined including a deleterious CO2 disproportionation process which produces (depe)2Fe­(CO) and (depe)2Fe­(CO3). Additionally, an intermediate iron–lactone complex in route to acrylate formation has been structurally characterized.

A study of the comparative reactivity of CO, CO2, tBuCN, and tBuNC with (C5Me5)2An­[P­(H)­Mes]2 (An = Th, U) has been undertaken. While CO2 and tBuNC form identical products with both metals, namely (C5Me5)2An­[κ2(O,O)-O2CPH­(Mes)]2 and (C5Me5)2An­[η2(tBuNCPMes]­(CNtBu), respectively, differing results are obtained with CO and tBuCN. The reaction of tert-butylnitrile with (C5Me5)2U­[P­(H)­Mes]2 in a 2:1 ratio leads to double insertion into the U–P bonds and elimination of H2PMes, forming the diketimido complex (C5Me5)2U­[κ2(N,N)-(NCtBu)2P­(Mes)]. This is a case in which the analogous reaction with (C5Me5)2Th­[P­(H)­Mes]2 affords a different product, (C5Me5)2Th­[PH­(Mes)]­[κ2(P,N)-N­(H)­C­(CMe3)­P­(Mes)]. The reaction of 1 atm of CO with (C5Me5)2U­[P­(H)­Mes]2 results in double insertion with proton migration from one phosphido ligand to one of the CO carbons to form (C5Me5)2U­[(κ2(O,O)-OCPMesC­(O)­(H)­P­(H)­Mes]. This is in contrast to the previously published result of the reaction between (C5Me5)2Th­[P­(H)­Mes]2 and CO, in which the product is similar, but both protons from the phosphido ligands migrate to one carbon atom, resulting in (C5Me5)2Th­[κ2(O,O)-OC­(H)2P­(Mes)­C­(O)­P­(Mes)]. Density functional theory calculations demonstrate that the mechanisms are quite similar and therefore a similar product is formed, except uranium is less acidic, and the final C–H bond formation does not occur.

We report the synthesis of a novel metal–organic capsule constructed from six pyrogallol[4]arene macrocycles, which are switched together by 16 FeIII and 16 CoII ions. This supramolecular structure is the first instance of a spheroidal heterometallic nanocage assembled through a one‐step metal–ligand coordination approach. This new assembly also demonstrates an important proof of concept through the formation of multiple heterometallic metal–metal interactions within the capsule framework. Photophysical and electrochemical studies of self‐assembled capsule films indicate their potential as semiconductors. These materials display unexpected photoelectric conversion properties, thus representing an emergent phenomenon in discrete metal–organic supramolecular assemblies.

We describe an example of a two-electron metal- and ligand-based reduction of Me3SiN3 using uranium(iv) complexes with varying steric properties. With uranium-based reduction, a U(vi) intermediate is isolated.

Oxidopyridinium ions bearing an ester group at the 5-position undergo (4 + 3) cycloaddition reaction to afford congeners of 7-azabicyclo[4.3.1]­decane. The reaction generally proceeds in high yield, although an excess of diene is often required to achieve such yields. The reaction is highly regioselective, but not endo/exo selective. It appears the cycloaddition process can be either kinetically or thermodynamically controlled, depending on the nature of the diene used and the reaction time. An intramolecular Heck reaction was used to demonstrate that some chemistry is possible with the cycloadducts.

In continuing to examine the interaction of actinide-ligand bonds with soft donor ligands, a comparative investigation with phosphorus and arsenic was conducted. A reaction of (C 5 Me 5 ) 2 AnMe 2 , An = Th, U, with 2 equiv of H 2 AsMes, Mes = 2,4,6-Me 3 C 6 H 2 , forms the primary bis(arsenido) complexes, (C 5 Me 5 ) 2 An[As(H)Mes] 2 . Both exhibit thermal instability at room temperature, leading to the elimination of H 2 , and the formation of the diarsenido species, (C 5 Me 5 ) 2 An(η 2 -As 2 Mes 2 ). The analogous diphosphido complexes, (C 5 Me 5 ) 2 An(η 2 -P 2 Mes 2 ), could not be synthesized via the same route, even upon heating the bis(phosphido) species to 100 °C in toluene. However, they were accessible via the reaction of dimesityldiphosphane, MesP(H)P(H)Mes, with (C 5 Me 5 ) 2 AnMe 2 at 70 °C in toluene. When (C 5 Me 5 ) 2 AnMe 2 is reacted with 1 equiv of H 2 AsMes, the bridging μ 2 -arsinidiide complexes [(C 5 Me 5 ) 2 An] 2 (μ 2 -AsMes) 2 are formed. Upon reaction of (C 5 Me 5 ) 2 UMe 2 with 1 equiv of H 2 PMes, the phosphinidiide [(C 5 Me 5 ) 2 U(μ 2 -PMes)] 2 is isolated. However, the analogous thorium reaction leads to a phosphido and C−H bond activation of the methyl on the mesityl group, forming {(C 5 Me 5 ) 2 Th[P(H)(2,4-Me 2 C 6 H 2 -6-CH 2 )]} 2 . The reactivity of [(C 5 Me 5 ) 2 An(μ 2 -EMes)] 2 was investigated with OPPh 3 in an effort to produce terminal phosphinidene or arsinidene complexes. For E = As, An = U, a U(III) cation−anion pair [(C 5 Me 5 ) 2 U(η 2 -As 2 Mes 2 )][(C 5 Me 5 ) 2 U(OPPh 3 ) 2 ] is isolated. The reaction of [(C 5 Me 5 ) 2 Th(μ 2 -AsMes)] 2 with OPPh 3 does not result in a terminal arsinidene but, instead, eliminates PPh 3 to yield a bridging arsinidiide/oxo complex, [(C 5 Me 5 ) 2 Th] 2 (μ 2 -AsMes)(μ 2 -O). Finally, the combination of [(C 5 Me 5 ) 2 U(μ 2 -PMes)] 2 and OPPh 3 yields a terminal phosphinidene, (C 5 Me 5 ) 2 U(PMes)(OPPh 3 ), featuring a short U−P bond distance of 2.502(2) Å. Electrochemical measurements on the uranium pnictinidiide complexes demonstrate only a 0.04 V difference with phosphorus as a slightly better donor. Magnetic measurements on the uranium complexes show more excited-state mixing and therefore higher magnetic moments with the arsenic-containing compounds but no deviation from uncoupled U(IV) behavior. Finally, a quantum theory of atoms in molecules analysis shows highly polarized actinide-pnictogen bonds with similar bonding characteristics, supporting the electrochemical and magnetic measurements of similar bonding between actinide-phosphorus and actinide-arsenic bonds.