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N-heterocyclic carbene and cyclic (alkyl)(amino)carbene complexes of molybdenum() and tungsten()
Ist Teil von
Dalton transactions : an international journal of inorganic chemistry, 2022-12, Vol.51 (47), p.18337-18352
Ort / Verlag
England: Royal Society of Chemistry
Erscheinungsjahr
2022
Quelle
Alma/SFX Local Collection
Beschreibungen/Notizen
The synthesis and characterization of N-heterocyclic carbene (NHC) and cyclic (alkyl)(amino)carbene (cAAC) complexes of molybdenum(
iv
) and tungsten(
iv
) chloride is reported. Reaction of two equivalents of the NHCs IMes (1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene), IDipp (1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene) and IiPr
Me
(1,3-diisopropyl-4,5-dimethylimidazolin-2-ylidene) with [MCl
4
(SEt)
2
] (M = Mo, W) in toluene afforded the bis-NHC complexes [MCl
4
(NHC)
2
] (M = Mo: NHC = IMes
1
, NHC = IMes
2
; M = W: NHC = IMes
3
, NHC = IDipp
4
, NHC = IiPr
Me
5
). Mono-carbene complexes [MCl
4
(NHC)(SEt
2
)]
6-9
(M = Mo: NHC = IMes
6
, NHC = IMes
7
; M = W: NHC = IMes
8
, NHC = IDipp
9
) are available
via
ligand dismutation of
1-4
with [MCl
4
(SEt)
2
]. Complexes
1-9
were characterized by using elemental analysis, IR- and multinuclear NMR spectroscopy and X-ray diffraction for
1-8
. The reactivity of the mono-NHC complexes
6-9
towards the cyclic (alkyl)(amino)carbene cAAC
Me
as well as the two electron donor ligands trimethylphosphine, triphenylphosphine, pyridine (py) and
N
,
N
-dimethylpyridin-4-amine (DMAP) was studied, which led to the synthesis of the mixed substituted complexes [MCl
4
(NHC)(cAAC
Me
)] (M = Mo: NHC = IMes
10
, NHC = IDipp
11
; M = W: NHC = IMes
12
, NHC = IDipp
13
), [MCl
4
(NHC)(PR
3
)] (M = W: NHC = IMes, R = Me
14
, NHC = IMes, R = Ph
15
, NHC = IDipp, R = Me
16
, NHC = IDipp, R = Ph
17
), [MCl
4
(NHC)(py)] (M = Mo: NHC = IMes
18
, NHC = IDipp
20
; M = W: NHC = IMes
22
, NHC = IDipp
24
) and [MCl
4
(NHC)(DMAP)] (M = Mo: NHC = IMes
19
, NHC = IDipp
21
; M = W: NHC = IMes
23
, NHC = IDipp
25
).
The synthesis, characterization, and molecular structures of NHC and cAAC
Me
stabilized Mo(
iv
) and W(
iv
) complexes are presented.