Unsymmetric Ir2 and RhIr Dinuclear Complexes Supported by a Linear Tetraphosphine meso-dpmppp, Showing High Reactivity for O2, H2, and HCl

• Published in: Inorganic chemistry 2024-10, Vol.63 (42), p.19847-19863
• Main Authors: Nakajima, Takayuki, Kotani, Momoko, Maeda, Yuki, Sato, Miwa, Iwai, Kento, Tanase, Tomoaki
• Format: Article
• Language: English
• ISSN: 0020-1669; 1520-510X; 1520-510X
• DOI: 10.1021/acs.inorgchem.4c03241

Unsymmetric dinuclear Ir­(I) complexes, [Ir2Cl2(L)­(meso-dpmppp)] (L = XylNC (1aIr 2 ), t BuNC (1bIr 2 ), CO (1cIr 2 )), were synthesized using meso-Ph2PCH2P­(Ph)­(CH2)3P­(Ph)­CH2PPh2 (meso-dpmppp), which supports cis-P,P (M1) and trans-P,P (M2) metal sites, and exhibited high reactivity for O2, H2, and HCl. The IrRh heterodinuclear complexes, [M1M2Cl2(L)­(meso-dpmppp)] (1 x M 1 M 2 ) (M1M2 = IrRh, RhIr; L = XylNC, CO ( x = a, c)), were also synthesized and used together with the Rh2 complexes (1a,cRh 2 ) to elucidate the role of each metal site. For the reactions of O2, 1aIr 2 and 1aRhIr showed higher reactivity than those of 1aIrRh and 1aRh 2 , giving η2–peroxide complexes [{M1Cl2}­{M2(η2–O2)­(XylNC)}­(meso-dpmppp)] (2aIr 2 , 2aRhIr), from which O2 would not dissociate. All the CO complexes 1cM 1 M 2 (M1, M2 = Ir or Rh) showed no reactivity for O2. In the reactions with H2, 1aIr 2 reacted with H2 to give the dihydride complex, [{IrCl2}­{Ir­(H)2L}­(meso-dpmppp)] (11aIr 2 ) and the tetrahydride complex, [{Ir­(H)­Cl2}­(μ–H)­{Ir­(H)2L}­(meso-dpmppp)] (12aIr 2 ), while 1aRhIr gave the dihydride complex, and 1aIrRh and 1aRh 2 gave no hydride complexes. Reactions of 1a,cM 1 M 2 with HCl afforded the dihydride complexes, [{IrCl3}­(μ–H)­{Ir­(H)­Cl­(XylNC)}­(meso-dpmppp)] (14aIr 2 ), [{Ir­(H)­Cl2}­(μ–H)­{M2Cl2(L)}­(meso-dpmppp)] (M2 = Ir, L = CO (15cIr 2 ); M2 = Rh, L = XylNC (15aIrRh), CO (15cIrRh)), and [{Rh­(H)­Cl2}­(μ–Cl)­{Ir­(H)­Cl­(XylNC)}­(meso-dpmppp)] (18aRhIr), the structures varying depending on M1 and M2 as well as L.