1616064-08-4Relevant articles and documents
Reversible Coordination of Boron-, Aluminum-, Zinc-, Magnesium-, and Calcium-Hydrogen Bonds to Bent {CuL2} Fragments: Heavy σ Complexes of the Lightest Coinage Metal
Hicken, Alexandra,White, Andrew J. P.,Crimmin, Mark R.
, p. 8669 - 8682 (2017)
A series of copper(I) complexes bearing electron-deficient β-diketiminate ligands have been prepared. The study includes [{{ArNC(CR3)}2CH}Cu(η2-toluene)n] (Ar = Mes, R = F, n = 0.5, [12·tol]; Ar = C6F5, R = Me, n = 1, [2·tol]; Ar = 2,6-Cl2C6H3, R = H, n = 0.5, [32·tol]). Reactions of [1-3n·tol] with boranes, alanes, a zinc hydride, a magnesium hydride, and a calcium hydride generate the corresponding σ complexes ([1-3·B], [3·B′], [3·Al], [3·Al′], [1-3·Zn], [1·Mg], and [1·Ca]). These species all form reversibly, being in equilibrium with the arene solvates in solution. With the exception of the calcium complex, the complexes have all been characterized by single-crystal X-ray diffraction studies. In solution, the σ-hydride of the aluminum, zinc, magnesium, and calcium derivatives resonates between -0.12 and -1.77 ppm (C6D6 or toluene-d8, 193-298 K). For the σ-borane complexes, the hydrides are observed as a single resonance between 2 and 3.5 ppm (C6D6, 298 K) and bridging and terminal hydrides rapidly exchange on the NMR time scale even at 193 K. Quantification of the solution dynamics by van't Hoff analysis yields expectedly small values of ΔH° and negative values of ΔS° consistent with weak binding and a reversible process that does not involve aggregation of the copper species. The donor-acceptor complexes can be rationalized in terms of the Dewar-Chatt-Duncanson model. Density functional theory calculations show that the donation of σ-M-H (or E-H) electrons into the 4s-based orbital (LUMO or LUMO+1) of the copper fragment is accompanied by weak back-donation from a dxz-based orbital (HOMO or HOMO-1) into the σ?-M-H (or E-H) orbital.
Synthesis and structures of fluorinated (β-diketiminato)rhodium complexes: Si-H activation of silanes at a carbonyl complex
Meier, Gregor,Steck, Viktoria,Braun, Beatrice,Ei?ler, Anna,Herrmann, Roy,Ahrens, Mike,Laubenstein, Reik,Braun, Thomas
, p. 2793 - 2808 (2014/06/24)
The (β-ketiminato)rhodium complex [Rh{κ2-(N,O)-(tBu) (O)CCHC(tBu)N(C6F5)}(cod)] (1) [cod = (1Z,5Z)-1,5- cyclooctadiene] and (β-diketiminato)rhodium complexes [Rh{κ 2-(N,N)-(Ar)NC(Me)CHC(Me)N(Ar)}(L1)(L2)] [2: Ar = C6F5, (L1)(L2) = cod; 3: Ar = C6F5, L1 = L2 = C2H 4; 4: Ar = C6F5, L1 = L2 = CNtBu; 5: Ar = 2,6-MeC6H3, L1 = L2 = CNtBu; 6a: Ar = C6F5, L1 = L2 = CO; 7a: Ar = C6F5, L1 = CO, L2 = NCMe; 8a: Ar = C6F5, L1 = CO, L2 = PEt3; 9a: Ar = C6F5, L1 = CO, L 2 = NH3] were synthesized. Treatment of [Rh{κ2-(N,N)-(C6F5)NC(Me)CHC(Me)N(C 6F5)}(CO)(NCMe)] (7a) with tertiary silanes HSiR 3 gave the (β-diketiminato)(hydrido)(silyl)rhodium complexes [Rh{κ2-(N,N)-(C6F5)NC(Me)CHC(Me)N(C 6F5)}(H)(SiR3)(CO)] (10a: R = Me; 11: R = Et; 12: R = iPr; 13: R = Ph; 14: R = OMe; 15: R = OEt). When using an excess amount of HSiMe3 the dihydridobis(silyl) complex [Rh{κ2-(N, N)-(C6F5)NC(Me)CHC(Me)N(C6F5)}(H) 2(SiMe3)2] (16) was formed in addition to 10a. A series of rhodium complexes with a fluorinated β-diketiminato ligand as well as a fluorinated β-ketiminato ligand has been synthesized. Treatment of [Rh{κ2-(N,N)-(C6F5)NC(Me)CHC(Me) N(C6F5)}(CO)(NCMe)] with tertiary silanes HSiR3 (R = Me, Et, iPr, Ph, OMe, OEt) gave the (β-diketiminato)(hydrido)(silyl) rhodium complexes [Rh{κ2-(N,N)-(C6F 5)NC(Me)CHC(Me)N(C6F5)}(H)(SiR 3)(CO)]. Copyright
