Addition compounds between carbones, CL2, and main group Lewis acids: A new glance at old and new compounds

Double dative bond between divalent carbon(0) and uranium

“…In contrast, examples containing a double dative bond, which donates two lone electron pairs to the same acceptor are rare 34–37 . A comparative experimental work showed that carbenes and carbones exhibit distinctively different complexation behavior due to the varying number of lone-pair orbitals 32 . The chemistry of divalent carbon(0) has been focused mainly on main group compounds and transition metal element complexes.…”

Ligands Based on Phosphine‐Stabilized Aluminum(I), Boron(I), and Carbon(0)

“…Interestingly,t he interaction energy for the protonated CDP ligand (E = CH) is too low to compensate for the preparation energy,w hich results in an overall negative dissociatione nergy.T hese findings suggest that the corresponding iron complex 2c is not stable towardsF e ÀCb ond dissociation,w hich is indeed often observed upon protonation of CDP complexes. [7,17] The deformation densities in variant IV predominantly show s donation of the phosphine lone pairs to the iron-bound group E. In the case of variant IV,aninverse trend for the interaction energies (DE int )i so bserved, in comparison to that of variant III.The interaction between the phosphines andcoordinated AlH fragment is by far the weakest, followed by E = BH and E = C. Thes trongest interaction is observed for protonated CDP (E = CH). Except for the aluminum-based complex,a ttractive interactions between the fragments in variant IV are domi-nated by contributions from orbital interactions.…”

“…This is in agreement with previouse xperimentalo bservations that monodentate CDP adducts dissociate in most cases upon protonation. [7,17,30,31] Analysis of the octahedral 3d metal complexes with aformal d 6 -electronc ount reveals the impact of varying chargei nM n + , Fe 2 + ,a nd Co 3 + on different contributions to the investigated metal-ligand bond ( Table 6). For neutral ligands (E = AlH, BH, C), DE int and D e increasef rom Mn + to Co 3 + .T his is ar esult of stronger orbitala nd electrostatic interactions upon going from Mn + to Fe 2 + and Co 3 + ,w hich are compensated for to differing extentsb yt he Pauli repulsion.…”

“…Carbodiphosphoranes (CDPs) represent an early example of divalent carbon compounds, in which the bonding situation can be understood in terms of ad onor-acceptor interaction between a single carbon atom in an exited D 1 state and two phosphine ligands with the ability for s-type donation and p-type back donation. [1][2][3][4][5][6][7] In general,t hey exhibit ah igh proton affinity and high tendency to form all kindso fadducts and coordination compounds with Lewis acid or metal fragments.W ith the two lone pairs of s and p symmetry,C DPs can potentially act as s and p donors, respectively,a nd are particularly good ligands for electron-deficientt ransition metals. Due to the unusual binding properties, increasedc atalytic activity has been predictedw ith these ligands (e.g.,i no lefin metathesis).…”

Donor‐Stabilized Silylene/Phosphine‐Supported Carbon(0) Center with High Electron Density

“…They can therefore be used both as s-a nd p-donor ligands with apowerful electron-donating ability,which is far stronger than that of classical NHCs, [3] and the introduction of different donating ligands (L) diversifies their properties and reactivities. [4][5][6] Particularly,c arbodiphosphoranes (CDPs; IV), first reported by Ramirez in 1961, [7] are one of the most representative compounds in this category [8,9] and their double s-a nd p-donating effects were well demonstrated by the efficient stabilization of the highly reactive dihydro borenium cation (BH 2 + ). [10] Moreover,c yclic CDPs (V)a re the most strongly donating ligands known.…”