TY - JOUR

T1 - Cleavage of acyclic diaminocarbene ligands at an iridium(III) center. Recognition of a new reactivity mode for carbene ligands

AU - Kinzhalov, Mikhail A.

AU - Eremina, Anzhelika A.

AU - Smirnov, Andrey S.

AU - Suslonov, Vitalii V.

AU - Kukushkin, Vadim Yu.

AU - Luzyanin, Konstantin V.

PY - 2019/1/1

Y1 - 2019/1/1

N2 - Reaction of [Ir(μ-Cl)(ppy) 2] 2 (1) with 4 equivs of CNC 6H 4X (X = F 2a, Cl 2b, Br 2c, I 2d) in the presence of 2 equivs of AgOTf in dichloromethane at 20-25 °C furnished the bisisocyanide complexes [Ir(ppy) 2(CNC 6H 4X) 2](OTf) ([3a-d](OTf); 72-87%). Reaction of [3a-d](OTf) with an excess of gaseous ammonia at room temperature gave the bisdiaminocarbene species [Ir(ppy) 2{C(NH 2)NHC 6H 4X} 2](OTf) [5a-d](OTf) (73-83%); the two-step addition proceeds through an intermediate formation of appropriate monocarbene complexes [4a-d](OTf). Further reaction of [5a-d](OTf) with an excess of gaseous ammonia at 50 °C led to the cleavage of one diaminocarbene ligand to the cyanide ligand in [Ir(ppy) 2(CN){C(NH 2)NHC 6H 4X}] (6a-d) and this transformation is accompanied with the elimination of a substituted aniline. Treatment of [5a-d](OTf) with N(CH 2CH 2OH) 3 at 50 °C resulted in the cleavage of the diaminocarbene ligand to the isocyanide and uncomplexed NH 3; isocyanide remains bound to the iridium(iii) center in [Ir(ppy) 2{C(NH 2)NHC 6H 4X}(CNC 6H 4X)](OTf) (4a-d). All isolated compounds were characterized by elemental analyses (C, H, N), molar conductivity measurements, TG/DTA, HRESI +/--MS, FTIR, 1D ( 1H, 13C{ 1H}, 19F{ 1H}) and 2D ( 1H, 1H-COSY, 1H, 13C-HMQC/ 1H, 13C-HSQC, 1H, 13C-HMBC) NMR, and also by X-ray diffraction (for the bisisocyanide 3, the diaminocarbene/isocyanide 4, the bisdiaminocarbene 5, and the diaminocarbene/cyanide 6 type complexes).

AB - Reaction of [Ir(μ-Cl)(ppy) 2] 2 (1) with 4 equivs of CNC 6H 4X (X = F 2a, Cl 2b, Br 2c, I 2d) in the presence of 2 equivs of AgOTf in dichloromethane at 20-25 °C furnished the bisisocyanide complexes [Ir(ppy) 2(CNC 6H 4X) 2](OTf) ([3a-d](OTf); 72-87%). Reaction of [3a-d](OTf) with an excess of gaseous ammonia at room temperature gave the bisdiaminocarbene species [Ir(ppy) 2{C(NH 2)NHC 6H 4X} 2](OTf) [5a-d](OTf) (73-83%); the two-step addition proceeds through an intermediate formation of appropriate monocarbene complexes [4a-d](OTf). Further reaction of [5a-d](OTf) with an excess of gaseous ammonia at 50 °C led to the cleavage of one diaminocarbene ligand to the cyanide ligand in [Ir(ppy) 2(CN){C(NH 2)NHC 6H 4X}] (6a-d) and this transformation is accompanied with the elimination of a substituted aniline. Treatment of [5a-d](OTf) with N(CH 2CH 2OH) 3 at 50 °C resulted in the cleavage of the diaminocarbene ligand to the isocyanide and uncomplexed NH 3; isocyanide remains bound to the iridium(iii) center in [Ir(ppy) 2{C(NH 2)NHC 6H 4X}(CNC 6H 4X)](OTf) (4a-d). All isolated compounds were characterized by elemental analyses (C, H, N), molar conductivity measurements, TG/DTA, HRESI +/--MS, FTIR, 1D ( 1H, 13C{ 1H}, 19F{ 1H}) and 2D ( 1H, 1H-COSY, 1H, 13C-HMQC/ 1H, 13C-HSQC, 1H, 13C-HMBC) NMR, and also by X-ray diffraction (for the bisisocyanide 3, the diaminocarbene/isocyanide 4, the bisdiaminocarbene 5, and the diaminocarbene/cyanide 6 type complexes).

KW - ACIDITIES

KW - BLUE PHOSPHORESCENCE

KW - BOND ACTIVATION

KW - COMPLEXES

KW - CRYSTAL-STRUCTURES

KW - ISOCYANIDE

KW - ISONITRILES

KW - N-HETEROCYCLIC CARBENES

UR - http://www.scopus.com/inward/record.url?scp=85066729416&partnerID=8YFLogxK

UR - http://www.mendeley.com/research/cleavage-acyclic-diaminocarbene-ligands-iridium-iii-center-recognition-new-reactivity-mode-carbene-l

U2 - 10.1039/C9DT01138B

DO - 10.1039/C9DT01138B

M3 - Article

VL - 48

SP - 7571

EP - 7582

JO - Dalton Transactions

JF - Dalton Transactions

SN - 1477-9226

IS - 22

ER -