Page 5 of 7
New Journal of Chemistry
Please do not adjust margins
NJC
ARTICLE
1
2
3
4
5
9
n-C6H13CH(OH)CH3
n-C6H13CH(OH)CH3
1
2
100
84
n-C6H13COCH3 (80)
n-C6H13COCH3 (78)
25
DOI: 10.1039/D0NJ05752E
10
21
6
7
8
9
aReaction conditions: cluster 1 or 2 (5 μmol), benzyl alcohol, p-methylbenzyl alchol, cyclohexanol, 1-octanol, and 2-octanol (2
mmol), reaction temperature 120 C. Turnover number (TON) after 72 h. Determined by GC using naphthalene as an internal
standard. Yield = sum of oxidation products (mol)/initial substrate (mol)×100. dAfter 96 h.
o
b
c
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Table 1 Catalytic activities for oxidation of alcohols with
phosphovanadomolybdates 1 and 2a.
1 atm molecular oxygen catalyzed by Ru-containing
catalysts for the oxidation of alcohols using 1 atm of molecular
oxygen. The selectivity for oxidation of 2-octanol to 2-octanone
improved from 32% to 80%.29 Design and synthesis of other
ruthenium-supported polyoxometaltes as effective catalysts for
oxidation of organic substrate are undergoing in our laboratory.
Catalytic activities of clusters 1 and 2 were examined for the
oxidation of several alcohols, including benzyl alcohol, p-
methylbenzyl alcohol, cyclohexanol, 1-octanol and 2-octanol, with 1
atm oxygen molecule at 120 ºC, as summarized in Table 1. The
oxidation of benzyl alcohol gave benzaldehyde as the main product
(selectivity: 92% catalyzed by cluster 1, 94% catalyzed by cluster 2),
and a little benzoic acid was also detected (selectivity: 8% for 1, 6%
for 2) (Entries 1, 2). The conversion of benzyl alcohol using cluster 1
is 80% (TON = 320), a little lower than that of 84% by employment of
cluster 2 (TON = 336). Similar results were observed for oxidation of
p-methylbenzyl alcohol (Entries 3, 4). The conversion and selectivity
of oxidation of benzyl alcocol/p-methylbenzyl alcohol catalyzed by
heteropolyoxometalates 1 and 2 could not reach the catalytic
behavior of the ruthenium-supported homopolyoxometalate
Acknowledgements
This project was supported by Natural Science Foundation of
Anhui Province (2008085MB58).
References
[Ru(dmso)3Mo7O24]4‒ (> 99% conversion and > 99% selectivity).29 The
catalytic behavior of clusters 1 and 2 towards oxidation of 1-octanol
and 2-octanol was poor compared to the relatively good catalytic
result of cyclohexanol. However, the selectivity for the conversion of
2-octanol to 2-octanone catalyzed by heteropolyoxometalates 1
1
C. J. Hill and C. M. Prosser-McCartha, Coord. Chem. Rev., 1995,
143, 407.
J. J. Walsh, A. M. Bond, R. J. Forster and T. E. Keyes, Coord.
Chem. Rev., 2016, 306, 217.
I. A. Weinstock, R. E. Schreiber and R. Neumann, Chem. Rev.,
2018, 118, 2680.
D. D. Li, P. T. Ma, J. Y. Niu and J. P. Wang, Coord. Chem. Rev.,
2019, 392, 49.
J. X. Liu, X. B. Zhang, Y. L. Li, S. L. Huang, G. Y. Yang, Coord.
Chem. Rev., 2020, 414, DOI: 10.1016/j.ccr.2020.213260.
H. Wu, H.-K. Yang and W. Wang, New J. Chem., 2016, 40, 886.
R. Cao, T. M. Anderson, P. M. B. Piccoli, A. J. Schultz, F. K.
Thomas, Y. V. Geletii, E. Slonkina, B. Hedman, K. O.
Hodgson, K. I. Hardcastle, X.-K. Fang, M. L. Kirk, S.
Knottenbelt, P. Kögerler, D. G. Musaev, K. Morokuma, M.
Takahashi and C. L. Hill, J. Am. Chem. Soc., 2007, 129, 11118.
Nadjo and U. Kortz, Angew. Chem., Int. Ed., 2010, 49, 1886.
T. M. Anderson, R. Cao, E. Slonkina, K. O. Hodgson, K. I.
Hardcastle, W. A. Neiwert, S. -X. Wu, M. L. Kirk, S. Knottenbelt,
E. C. Depperman, B. Keita, L. Nadjo, D. G. Musaev, K.
Morokuma and C. L. Hill, J. Am. Chem. Soc., 2008, 130, 2877.
2
3
4
5
(80%) and
2
(78%) was much higher than that of
homopolyoxometalate [Ru(dmso)3Mo7O24]4‒ (32% selectivity).29
Control reactions with cis-[RuCl2(dmso)4] as catalyst showed no
29
oxidation for benzyl alcohol
.
Additionally, [PMo12O40]3‒,
6
7
[Mo6O19]2‒, [MoO4]2‒, and [α2-P2W17O61]10‒ species could not
catalyze aerobic oxidation of benzyl alcohol either.29,
36
Combination of the ruthenium fragment and polyoxometalte unit
in clusters 1 and 2 may lead to the formation of the key metal-
alcoholate intermediate easily in the catalytic aerobic oxidation
system.29,36
8
9
Conclusions
10 L. -H. Bi, M. Reicke, U. Kortz, L. Nadjo and R. J. Clark, Inorg.
Chem., 2004, 43, 3915.
11 L. -H. Bi, U. Kortz, B. Keita, L. Nadjo and H. Borrmann, Inorg.
Chem., 2004, 43, 8367.
12 L. -H. Bi, U. Kortz, B. Keita, L. Nadjo and L. Daniels, Eur. J. Inorg.
Chem., 2005, 3034.
13 N. V. Izarova, R. N. Biboum, B. Keita, M. Mifsud, I. W. C. E.
Arends, G. B. Jamesond and U. Kortz, Dalton Trans., 2009,
9385.
14 N. V. Izarova, M. H. Dickman, R. N. Biboum, B. Keita, L. Nadjo,
V. Ramachandran, N. S. Dalal and U. Kortz, Inorg. Chem., 2009,
48, 7504.
15 L.-H. Bi, M. H. Dickman and U. Kortz, CrystEngCommun, 2009,
11, 965.
16 E. V. Chubarova, M. H. Dickman, B. Keita, L. Nadjo, F. Miserque,
Two
stable
ruthenium(II)-substituted
phosphovanadomolybdates [RuII(dmso)3PMoVI6VV O32]6‒ (1)
3
and [RuII(PMoVI6VV O32)2]14‒ (2) are synthesized by self-assembly
3
of cis-[RuCl2(dmso)4], NaVO3, Na2MoO4 and NaH2PO4 in HOAc-
NaOAc solution. The oxidation states of ruthenium(II),
vanadium(V) and molybdenum(VI) in clusters 1 and 2 are not
changed compared to the corresponding reactants, which are
confirmed by bond valence sum calculations.50,51 While in other
hydrothermally synthesized phosphovanadomolybdates, mixed
valences of molybdenum(VI/V) and vanadium(IV) were usually
24
observed,
such
as
[PMoVI5MoV VIV8O44]6‒
and
3
[PMoVI8MoV VIV4O32]5‒.25 The new ruthenium-supported
2
polyoxometalates are found to be effective heterogeneous
This journal is © The Royal Society of Chemistry 20xx
New J. Chem. | 5
Please do not adjust margins