Doddi Adinarayana, Bockfeld Dirk, Bannenberg Thomas, Tamm Matthias
Department of Chemical Sciences, Indian Institute of, Science Education and Research Berhampur, Transit Campus, Govt. ITI Building, Engineering School Road, Ganjam, Berhampur, 760010, Odisha, India.
Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106, Braunschweig, Germany.
Chemistry. 2020 Nov 20;26(65):14878-14887. doi: 10.1002/chem.202003099. Epub 2020 Oct 6.
Chloride abstraction from the complexes [(η -p-cymene){(IDipp)P}MCl] (2 a, M=Ru; 2 b, M=Os) and [(η -C Me ){(IDipp)P}IrCl] (3 b, IDipp=1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene) with sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (NaBAr ) in the presence of trimethylphosphine (PMe ), 1,3,4,5-tetramethylimidazolin-2-ylidene ( IMe) or carbon monoxide (CO) afforded the complexes [(η -p-cymene){(IDipp)P}M(PMe )]BAr ] (4 a, M=Ru; 4 b, M=Os), [(η -p-cymene){(IDipp)P}Os( IMe)]BAr ] (5) and [(η -C Me ){(IDipp)P}IrL][BAr ] (6, L=PMe ; 7, L= IMe; 8, L=CO). These cationic N-heterocyclic carbene-phosphinidene complexes feature very similar structural and spectroscopic properties as prototypic nucleophilic arylphosphinidene complexes such as low-field P NMR resonances and short metal-phosphorus double bonds. Density functional theory (DFT) calculations reveal that the metal-phosphorus bond can be described in terms of an interaction between a triplet [(IDipp)P] cation and a triplet metal complex fragment ligand with highly covalent σ- and π-contributions. Crystals of the C-H activated complex 9 were isolated from solutions containing the PMe complex, and its formation can be rationalized by PMe dissociation and formation of a putative 16-electron intermediate [(η -C Me )Ir{P(IDipp)}I][BAr ], which undergoes C-H activation at one of the Dipp isopropyl groups and addition along the iridium-phosphorus bond to afford an unusual η -benzyl coordination mode.
在三甲基膦（PMe₃）、1,3,4,5-四甲基咪唑啉-2-亚基（IMe）或一氧化碳（CO）存在的情况下，用四[3,5-双（三氟甲基）苯基]硼酸钠（NaBArF₂₄）从配合物[(η⁶-p-异丙基苯){(IDipp)P}MCl]（2a，M = Ru；2b，M = Os）和[(η⁶-C₆Me₆){(IDipp)P}IrCl]（3b，IDipp = 1,3-双（2,6-二异丙基苯基）咪唑啉-2-亚基）中提取氯离子，得到配合物[(η⁶-p-异丙基苯){(IDipp)P}M(PMe₃)][BArF₂₄]（4a，M = Ru；4b，M = Os）、[(η⁶-p-异丙基苯){(IDipp)P}Os(IMe)][BArF₂₄]（5）和[(η⁶-C₆Me₆){(IDipp)P}IrL][BArF₂₄]（6，L = PMe₃；7，L = IMe；8，L = CO）。这些阳离子型N-杂环卡宾-磷烯配合物具有与原型亲核芳基磷烯配合物非常相似的结构和光谱性质，如低场³¹P NMR共振和短的金属-磷双键。密度泛函理论（DFT）计算表明，金属-磷键可以用三重态[(IDipp)P]阳离子与具有高度共价σ和π贡献的三重态金属配合物片段配体之间的相互作用来描述。从含有PMe₃配合物的溶液中分离出了C-H活化配合物9的晶体，其形成可以通过PMe₃解离和假定的16电子中间体[(η⁶-C₆Me₆)Ir{P(IDipp)}I][BArF₂₄]的形成来解释，该中间体在Dipp异丙基之一处发生C-H活化，并沿铱-磷键加成，从而提供一种不寻常的η²-苄基配位模式。
