TY - JOUR
T1 - Activation and Photoinduced Release of Alkynes on a Biomimetic Tungsten Center
T2 - The Photochemical Behavior of the W−S-Phoz System
AU - Peschel, Lydia M.
AU - Vidovič, Carina
AU - Belaj, Ferdinand
AU - Neshchadin, Dmytro
AU - Mösch-Zanetti, Nadia C.
PY - 2019/3/12
Y1 - 2019/3/12
N2 -
The synthesis and structural determination of four tungsten alkyne complexes coordinated by the bio-inspired S,N-donor ligand 2-(4′,4′-dimethyloxazoline-2′-yl)thiophenolate (S-Phoz) is presented. A previously established protocol that involved the reaction of the respective alkyne with the bis-carbonyl precursor [W(CO)
2
(S-Phoz)
2
] was used for the complexes [W(CO)(C
2
R
2
)(S-Phoz)
2
] (R=H, 1 a; Me, 1 b; Ph, 1 c). Oxidation with pyridine-N-oxide gave the corresponding W-oxo species [WO(C
2
R
2
)(S-Phoz)
2
] (R=H, 2 a; Me, 2 b; Ph, 2 c). All W-oxo-alkyne complexes (2 a, b, c) were found to be capable of alkyne release upon light irradiation to afford five-coordinate [WO(S-Phoz)
2
] (3). The photoinduced release of the alkyne ligand was studied in detail by in situ
1
H NMR measurements, which revealed correlation of the photodissociation rate constant (2 b>2 a>2 c) with the elongation of the alkyne C≡C bond in the molecular structures. Oxidation of [WO(S-Phoz)
2
] (3) with pyridine-N-oxide yielded [WO
2
(S-Phoz)
2
] (4), which shows highly fluxional behavior in solution. Variable-temperature
1
H NMR spectroscopy revealed three isomeric forms with respect to the ligand arrangement versus each other. Furthermore, compound 4 rearranges to tetranuclear oxo compound [W
4
O
4
(μ-O)
6
(S-Phoz)
4
] (5) and dinuclear [{WO(μ-O)(S-Phoz)}
2
] (6) over time. The latter two were identified by single-crystal X-ray diffraction analyses.
AB -
The synthesis and structural determination of four tungsten alkyne complexes coordinated by the bio-inspired S,N-donor ligand 2-(4′,4′-dimethyloxazoline-2′-yl)thiophenolate (S-Phoz) is presented. A previously established protocol that involved the reaction of the respective alkyne with the bis-carbonyl precursor [W(CO)
2
(S-Phoz)
2
] was used for the complexes [W(CO)(C
2
R
2
)(S-Phoz)
2
] (R=H, 1 a; Me, 1 b; Ph, 1 c). Oxidation with pyridine-N-oxide gave the corresponding W-oxo species [WO(C
2
R
2
)(S-Phoz)
2
] (R=H, 2 a; Me, 2 b; Ph, 2 c). All W-oxo-alkyne complexes (2 a, b, c) were found to be capable of alkyne release upon light irradiation to afford five-coordinate [WO(S-Phoz)
2
] (3). The photoinduced release of the alkyne ligand was studied in detail by in situ
1
H NMR measurements, which revealed correlation of the photodissociation rate constant (2 b>2 a>2 c) with the elongation of the alkyne C≡C bond in the molecular structures. Oxidation of [WO(S-Phoz)
2
] (3) with pyridine-N-oxide yielded [WO
2
(S-Phoz)
2
] (4), which shows highly fluxional behavior in solution. Variable-temperature
1
H NMR spectroscopy revealed three isomeric forms with respect to the ligand arrangement versus each other. Furthermore, compound 4 rearranges to tetranuclear oxo compound [W
4
O
4
(μ-O)
6
(S-Phoz)
4
] (5) and dinuclear [{WO(μ-O)(S-Phoz)}
2
] (6) over time. The latter two were identified by single-crystal X-ray diffraction analyses.
KW - alkyne ligands
KW - bioinorganic chemistry
KW - photodissociation
KW - sulfur
KW - tungsten
UR - http://www.scopus.com/inward/record.url?scp=85061894468&partnerID=8YFLogxK
U2 - 10.1002/chem.201805665
DO - 10.1002/chem.201805665
M3 - Article
C2 - 30773712
AN - SCOPUS:85061894468
SN - 0947-6539
VL - 25
SP - 3893
EP - 3902
JO - Chemistry - a European Journal
JF - Chemistry - a European Journal
IS - 15
ER -