Suter Riccardo, Wagner Mona, Querci Lorenzo, Conti Riccardo, Benkő Zoltán, Grützmacher Hansjörg
Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093 Zurich, Switzerland.
Dalton Trans. 2020 Jun 23;49(24):8201-8208. doi: 10.1039/d0dt01864c.
Annulated oxy-substituted 1,3,4-azadiphospholides such as the anion in Na[1] are readily accessible phosphorus heterocycles made from the phosphaethynolate anion (OCP)- and 2-chloropyridines. The sodium salt Na[1] reacts with oxophilic element halides such as OPCl3, PhSiCl3, PhBCl2 and CpTiCl3 at room temperature to form exclusively the oxygen bound tris-substituted compounds E(1)3 (with E = OP, PhSi, PhB- or CpTi). Six equivalents of Na[1] with group four metal chlorides MCl4 (M = Ti, Zr, Hf) form cleanly the hexa-substituted dianions (Na2[M(1)6]) which are isolated in excellent yields. The titanium complexes are deeply coloured species due to ligand to metal charge transfer (LMCT) excitations. In all complexes, the phosphorus atoms of the azadiphosphole moieties are able to coordinate to a soft metal center as shown in their reactions with [Mo(CO)3Mes], yielding complexes in which the Mo(CO)3 binds in a fac manner. Functionalization of the oxy group with amino phosphanes allows isolation of tridentate ligands, which have been used as synthons for macrocyclic molybdenum carbonyl complexes.
环状氧取代的1,3,4 - 氮杂二磷杂环戊二烯化物，如Na[1]中的阴离子，是由磷乙炔醇根阴离子（OCP⁻）和2 - 氯吡啶制得的易于获得的磷杂环化合物。钠盐Na[1]在室温下与亲氧元素卤化物如OPCl₃、PhSiCl₃、PhBCl₂和CpTiCl₃反应，仅生成氧键合的三取代化合物E(1)₃（E = OP、PhSi、PhB或CpTi）。六当量的Na[1]与四族金属氯化物MCl₄（M = Ti、Zr、Hf）能顺利形成六取代的二价阴离子（Na₂[M(1)₆]），且产率极高。由于配体到金属的电荷转移（LMCT）激发，钛配合物是深色物种。在所有配合物中，氮杂二磷杂环戊二烯部分的磷原子能够与软金属中心配位，如它们与[Mo(CO)₃Mes]的反应所示，生成Mo(CO)₃以面式配位的配合物。用氨基膦对氧基团进行功能化可分离出三齿配体，这些配体已被用作大环钼羰基配合物的合成子。
