Loading…
Synthesis and reactivity of an iridium complex based on a tridentate aminophosphano ligand
The iridium( iii ) hydride compound [IrH{κ 3 C , P , P ′-(SiNP-H)}(CN t Bu) 2 ][PF 6 ] ( 1 PF 6 ) was obtained by reaction of [Ir(SiNP)(cod)][PF 6 ] with CN t Bu as the result of the intramolecular oxidative addition of the SiCH 2 -H bond to iridium( i ) [SiNP = Si(CH 3 ) 2 {N(4-tolyl)PPh 2 } 2 , Si...
Saved in:
| Published in: | Dalton transactions : an international journal of inorganic chemistry 2022-05, Vol.51 (18), p.7142-7153 |
|---|---|
| Main Authors: | , , |
| Format: | Article |
| Language: | English |
| Subjects: | |
| Citations: | Items that this one cites Items that cite this one |
| Online Access: | Get full text |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | The iridium(
iii
) hydride compound [IrH{κ
3
C
,
P
,
P
′-(SiNP-H)}(CN
t
Bu)
2
][PF
6
] (
1
PF
6
) was obtained by reaction of [Ir(SiNP)(cod)][PF
6
] with CN
t
Bu as the result of the intramolecular oxidative addition of the SiCH
2
-H bond to iridium(
i
) [SiNP = Si(CH
3
)
2
{N(4-tolyl)PPh
2
}
2
, SiNP-H = CH
2
Si(CH
3
){N(4-tolyl)PPh
2
}
2
]. The mechanism of the reaction was investigated by NMR spectroscopy and DFT calculations showing that the pentacoordinated intermediate [Ir(SiNP)(cod)(CN
t
Bu)][PF
6
] (
2
PF
6
) forms in the first place and that further reacts with CN
t
Bu, affording the square planar intermediate [Ir(SiNP)(CN
t
Bu)
2
][PF
6
] (
3
PF
6
) that finally undergoes the intramolecular oxidative addition of the SiCH
2
-H bond. The reactivity of
1
PF
6
was investigated. On one hand, the reaction of
1
PF
6
with
N
-chlorosuccinimide or
N
-bromosuccinimide provides the haloderivatives [IrX{κ
3
C
,
P
,
P
′-(SiNP-H)}(CN
t
Bu)
2
][PF
6
] (X = Cl,
4
PF
6
; Br,
5
PF
6
), and the reaction of
5
PF
6
with AgPF
6
in the presence of acetonitrile affords the solvato species [Ir{κ
3
C
,
P
,
P
′-(SiNP-H)}(CH
3
CN)(CN
t
Bu)
2
]
2+
(
6
2+
) isolated as the hexafluorophosphate salt. On the other hand, the reaction of
1
PF
6
with HBF
4
gives the iridium(
iii
) compound [IrH(CH
2
SiF
2
CH
3
)(HNP)
2
(CN
t
Bu)
2
][BF
4
] (
7
BF
4
) as the result of the formal addition of hydrogen fluoride to the Si-N bonds of
1
+
[HNP = HN(4-tolyl)PPh
2
]. A similar outcome was observed in the reaction of
1
PF
6
with CF
3
COOH rendering
7
PO
2
F
2
. In this case the intermediate [IrH{κ
2
C
,
P
-CH
2
SiMeFN(4-tolyl)PPh
2
}(HNP)(CN
t
Bu)
2
]
+
(
8
+
) was observed and characterised
in situ
by NMR spectroscopy. DFT calculations suggests that the reaction goes through the sequential protonation of the nitrogen atom of the Si-N-P moiety followed by the formal addition of fluoride ion to silicon. Also, the crystal structures of SiNP,
1
PF
6
,
4
PF
6
and
7
BF
4
have been determined by X-ray diffraction measurements.
Ligand fragmentation brought about by hydrogen fluoride addition to the Si-N bond in a hydrido iridium(
iii
) complex based on an aminophosphano ligand. |
|---|---|
| ISSN: | 1477-9226 1477-9234 |
| DOI: | 10.1039/d2dt00794k |