New gold (I) complexes with 5-aromatic ring-1, 3, 4-oxadiazole-2-thione and triphenylphosphine as potential multifunctional materials

Article abstract of DOI:10.1016/j.tetlet.2020.152668

Three new gold (I) complexes (4a, 4b, 4c) with 5-aromatic ring-1, 3, 4-oxadiazole-2-thione and triphenylphosphine as ligands were synthesized. Structures of 4a and 4b were determined through X-ray single-crystal diffraction, and it displayed that 4a and 4b had the same metal coordination pattern, wherein the ligand was coordinated by the sulfur atom to the central metal ion of gold (I). The optical properties of these gold (I) complexes were studied both in solution and in solid-state. In DMSO, 4a and 4b peaked at 415 nm and 443 nm, respectively, and the CIE coordinates of 4a and 4b in the solid-state were in the green area namely, (0.26, 0.46) and (0.24, 0.41). HOMO/LUMO levels and bandgaps of 4a, 4b and 4c were assessed by UV spectrum estimation, electrochemical method, and theoretical calculations. The observation hinted that the photophysical properties and energy levels of these gold (I) complexes can be adjusted by the introduction of different substituent aromatic rings at the 5-position of the 1, 3, 4-oxadiazole-2-thiol moiety. The findings of good optical, electrochemical and thermal properties of these new gold (I) complexes demonstrated their potential in the future studies as multifunctional materials.

Full text of DOI:10.1016/j.tetlet.2020.152668

Journal Pre-proofs
New gold (I) complexes with 5-aromatic ring-1, 3, 4-oxadiazole-2-thione and
triphenylphosphine as potential multifunctional materials
Yu Qiang Zhao, Jie Zhou, Renze He, Guang Ke Wang, Lan Xi Miao, Xiao
Guang Xie, Ying Zhou
PII:
S0040-4039(20)31179-5
DOI:
Reference:
https://doi.org/10.1016/j.tetlet.2020.152668
TETL 152668
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Tetrahedron Letters
Received Date:
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Accepted Date:
7 August 2020
5 November 2020
9 November 2020
Please cite this article as: Qiang Zhao, Y., Zhou, J., He, R., Ke Wang, G., Xi Miao, L., Guang Xie, X., Zhou, Y.,
New gold (I) complexes with 5-aromatic ring-1, 3, 4-oxadiazole-2-thione and triphenylphosphine as potential
multifunctional materials, Tetrahedron Letters (2020), doi: https://doi.org/10.1016/j.tetlet.2020.152668
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Tetrahedron Letters
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New gold (I) complexes with 5-aromatic ring-1, 3, 4-oxadiazole-2-thione and
triphenylphosphine as potential multifunctional materials
a
a
a
a
a
a
Yu Qiang Zhao , Jie Zhou , Renze He , Guang Ke Wang , Lan Xi Miao , Xiao Guang Xie and Ying
a,
Zhou 
a
College of Chemical Science and Technology, Yunnan University, Kunming, 650091, China
ARTICLE INFO
ABSTRACT

Corresponding author. Tel.: +86-871-65033715; fax: +86-871-65033715; e-mail: yingzhou@ynu.edu.cn
Article history:
Received
Received in revised form
Accepted
Three new gold (I) complexes (4a, 4b, 4c) with 5-aromatic ring-1, 3, 4-oxadiazole-2-thione and
triphenylphosphine as ligands were synthesized. Structures of 4a and 4b were determined
through X-ray single-crystal diffraction, and it displayed that 4a and 4b had the same metal
coordination pattern, wherein the ligand was coordinated by the sulfur atom to the central metal
ion of gold (I). The optical properties of these gold (I) complexes were studied both in solution
and in solid-state. In DMSO, 4a and 4b peaked at 415 nm and 443 nm, respectively, and the CIE
coordinates of 4a and 4b in the solid-state were in the green area namely, (0.26, 0.46) and (0.24,
Available online
0
.41). HOMO/LUMO levels and bandgaps of 4a, 4b and 4c were assessed by UV spectrum
estimation, electrochemical method, and theoretical calculations. The observation hinted that the
photophysical properties and energy levels of these gold (I) complexes can be adjusted by the
introduction of different substituent aromatic rings at the 5-position of the 1, 3, 4-oxadiazole-2-
thiol moiety. The findings of good optical, electrochemical and thermal properties of these new
gold (I) complexes demonstrated their potential in the future studies as multifunctional
materials.
Keywords:
Gold (I) complexes
Triphenylphosphine
Photoluminescence
Multifuctional material
2
009 Elsevier Ltd. All rights reserved.
complexes as solution-processable and vacuum-deposited
[15]
organic light-emitting diodes (OLEDs),
as well as specific
1
. Introduction
horizontally oriented gold (III) complexes that exhibit high
photoluminescence quantum yields of 70% and high horizontal
dipole ratio of 0.87, which were employed as green-emitting
OLEDs. [16]
In recent decades, gold complexes have been extensively
[1-
studied owing to their outstanding performance in many fields.
4
]
Their unique physiological activity has promoted numerous
researches on gold metal-organic complexes in anticancer,
Importantly, compared with extensive gold (III) complex
research, exploration of multi-functional gold (I) metal-organic
antibacterial and antiparasitic drugs.[5-6] In 2020, Chi-Ming Che et
[17-18]
al. reported various gold (III) mesoporphyrin IX dimethyl esters
complexes in photoluminescence is scarce.
Recently, gold
(
AuMesoIX) with thiol targeting ability, which showed effective
(I) complexes containing 1, 3, 4-oxadiazolines and phosphine
ligands have been reported as potential anticancer and
[7]
antitumor activity in ovarian cancer mouse models. In the same
year, Sylvie Garneau-Tsodikova and Samuel G. Awuah reported
[19-20]
antileishmanial agents.
Furthermore, the emission and
a series of gold (I)-phosphine complexes with potent inhibitory
activity for Candida Auris.[8] Additionally, Au complexes often
utilized in the field of chemical catalysts. Recently, Hashmi et al.
electronic transmission properties of gold (I) complexes are
rarely examined. Inspired by the novel structures and promising
properties of gold (I)-based 1, 3, 4-oxadiazole derivatives, we
studied the preparation of new gold (I) metal-organic complexes
with good photoluminescent and potential electron-transporting
properties that are applicable in the field of photoluminescence
and photoelectric.
reported gold metal-organic complexes for the purpose of C-H
[9]
activation, and Nakada et al. examined gold (I) as a catalyst for
catalytic ring isomerization reaction.[10]
In particular, the strong gold coordination bond and high spin
In this work, we designed and synthesized three new gold (I)
complexes (4a, 4b, and 4c) with 5-aromatic ring-1,3,4-
oxadiazole-2-thiol and triphenylphosphine ligands (Scheme 1).
The structures of complexes 4a and 4b were determined through
X-ray single-crystal diffraction, in which they displayed
comparable metal coordination patterns. Additionally, complexes
coupling constant endows gold metal-organic complex with high
stability and efficiency for triplet excitation capture.[11] Reports
have shown that certain luminescent gold (III) complexes possess
good photoelectric properties, and have been successfully applied
[12-13]
[14]
as emitting
and photovoltaics (PV) materials.
Vivian
Wing-Wah Yam et al. explored sky-blue-emitting gold (III)

2
Tetrahedron Letters
4
a and 4b displayed photoluminescence both in solution and
3
tertiary phosphine (PPh ) group in addition to the substitution
solid-state. The observed increase of electron donor capability of
the aromatic nucleus at 5 position of 1,3,4-oxadiazole-2-thiol,
promoted an obvious redshift in the UV-vis spectra of complexes
effect of the groups at 5-positon in 3a and 3b. (Table 2) The
closest Au···Au bond distances were found to be 3.536 Å (for
4a) and 4.773 Å (for 4b), larger than the sum of the van der
Waals radii (3.40 Å), and it, therefore, indicates there is no
significant gold−gold interaction in the two compounds. In the
complex 4b, intramolecular hydrogen bonds were formed by
O2−H2···N2 interactions, and weak non-classical intramolecular
hydrogen bonds formed by C8−H8···O1 interactions were
observed, with the Donor−Acceptor (D···A) distances being
2.673(5) and 2.872(5) Å, respectively. (Fig S40, Table S1)
4
a, 4b to 4c. In the solid phase, complexes 4a and 4b exhibited
strong green emission, while complex 4c showed no fluorescence
because of the obvious aggregation causing fluorescence
quenching. The HOMO/LUMO and band gaps (E ) the prepared
g
complexes were determined by optical tests, electrochemical
measurements and theoretical calculations. Semiconductor-like
band gaps with low LUMO energy level were found for complex
4
c, making it a potential candidate as electronic transport
material. Comparison of the complex’s properties showed that
their photophysical properties and energy levels could be
adjusted via the introduction of substitutes at the 5-position of
1
,3,4-oxadiazole-2-thiol ligand. Therefore, according to the
obtained results, with further rational design, some
multifunctional gold (I) complexes will have enormous potential
and prospects in the application of optoelectronic devices.
2
. Results and Discussion
Figure 1 (a) Schematic diagram of the smallest asymmetric unit structure of
2
.1. synthesis and structure
4
a; (b) Packing diagram for 4a, viewed along the b axis; (c) Schematic
diagram of the smallest asymmetric unit structure of 4b; (d) Packing diagram
for 4b, viewed along the a axis
The synthetic route to the compounds is shown in Scheme 1.
-membered aromatic acid or naphthoic acid was used as the
starting material for reaction with ethanol to form esters, wherein
DMAP and EDC were used as catalysts. Then the corresponding
6
Table 1. Crystal data and structure refinement parameters for compounds 4a
and 4b.
esters reacted with hydrazine hydrate (N
2
H
4
·H
2
O) and CS
2
to
4a
4b
form 1, 3, 4-oxadiazole-2-thiol ligands, 3a-3c in two steps. A
previously reported work has demonstrated that two tautomeric
forms of 1, 3, 4-oxadiazole-2-thione/thiol can coexist (Fig
S37), while the X-ray diffraction data for 4a and 4b (Table 2)
in this work indicate that the ligands 3a-3c presented a thiolate
form in the complexes. Triphenylphosphine gold chloride
Formula
Formula weight/g mol-1
C
27
H
22AuN
2
OPS
C
26
H
2 2
20AuN O PS
650.46
293(2)
652.44
293(2)
Temperature/K
Crystal system
Space group
a / Å
[20]
Monoclinic
C2/c
Triclinic
Pī
28.860(6)
8.8714(19)
20.482(5)
90
9.4161 (15)
10.8851(18)
11.888(2)
88.152(2)
86.769(2)
82.293(2)
1205.2(3)
2
3
(AuCl(PPh )) was dissolved along with the corresponding ligands
b / Å
in a mixed solvent system of acetone/dichloromethane (1:1) to
form the target complexes. Structures of the intermediates and
c / Å
α / °
1
13
final products have been verified by H NMR, C NMR, and
HR-MS. (Fig S3-S39)
β / °
111.494(2)
90
γ / °
V/ Å3
4879.2(18)
8
O
O
O
EtOH
NH2NH2 H2O
EtOH
CS2
NH2
Z
R
N
R
OH
R
O
KOH,EtOH
DMAP/EDC
CH2Cl2
H
Crystal size / mm3
0.330 x 0.210 x 0.210
0.48 × 0.25 ×0.230
1
a-1c
2a-2c
D
calc / g·cm-3
μ/ mm-1
F(000)
1.771
6.204
1.798
6.283
632
O
AuCl(PPh3)
O
OH
R
SH
R
S
Au(PPh3)
R=
Acetone/EtOH
N
N
N
N
2528
3a-3c
4a-4c
R
int
0.0312]
0.0224]
–11 ≤ h ≤ 11
–12 ≤ k ≤ 12
–14 ≤ l ≤ 14
1.039
a
b
c
–
34 ≤ h ≤ 34
S
Au(PPh3)
S
N
Au(PPh3)
S
Au(PPh3)
Limiting indices
–10 ≤ k ≤ 6
–24 ≤ l ≤ 24
1.107
O
O
O
N
N
N
Goodness-of-fit on F2
N
N
R
wR
R
wR
1
= 0.0281
1
R = 0.0236
OH
Final R indices [I>2sigma(I)]
2
= 0.0741
= 0.0414
= 0.0947
wR
2
= 0.0613
1
R = 0.0286
1
4a
4b
4c
R indices (all data)
2
wR
2
= 0.0636
-
Largest diff. peak and hole/(e·Å
Scheme 1.Synthetic processes and methods for compounds 1a-1c, 2a-2c, 3 a-
0
.568/ -1.068
0.49/-0.664
3
)
3
c, 4a-4c
a
|; b wR
2
2)2 / Σ w(F
2 2 1/2
R
1
= Σ ||F
o
| – |F
c
|| / Σ |F
o
2
= [Σ w(F
o
– F
c
o
) ]
Fortunately, the crystals of 4a and 4b were obtained by the
solvent dispersion method (dichloromethane/diethyl ether), and
their structures were determined by single-crystal X-ray
diffraction. The crystal data and structure refinement details for
the complexes 4a and 4b are summarized in Table 1. From the
data, it is evident that 4a and 4b have the same metal-
coordination pattern, in which the ligand is coordinated to the
central metal ion of gold(I) via the sulfur atom, which is
consistent with the previously reported two-coordinated gold(I)
Table 2. Selection of the main geometric parameters, bond lengths and bond
angles to the 4a and 4b
4a
Bond lengths
Au(1)-P(1)
Au(1)-S(1)
N(1)-N(2)
S(1)-C(9)
[Å]
Bond angles
P(1)-Au(1)-S(1)
C(9)-S(1)-Au(1)
C(10)-P(1)-Au(1)
C(16)-P(1)-Au(1)
C(22)-P(1)-Au(1)
N(2)-C(9)-S(1)
O(1)-C(9)-S(1)
[Å]
2.2628(14)
2.3030(16)
1.428(7)
1.719(6)
178.48(5)
103.75(19)
112.66(18)
113.58(17)
114.35(19)
126.1(4)
[20-23]
compounds.
The bond angles of P(1)-Au(1)-S(1) = 178.87°
(for 4a) and P(1)-Au(1)-S(1) = 177.83° (for 4b) revealed that the
coordinated sphere deviated slightly from the linear geometry in
these complexes, which may be related to the steric effect of the
122.0(4)

4
b
4b in the DMSO solution and powder state peaked at 415 nm/500
nm and 443 nm/509 nm, with the Stokes shifts being 73 nm/ 158
nm and 93 nm/ 159 nm, respectively. The greater stokes shift in
solid state showed that the intermolecular interaction increases
the non-radiative relaxation of the excited state energy in solid. In
these three complexes, the strongest π-π accumulation effects of
Bond lengths
Au(1)-P(1)
Au(1)-S(1)
N(1)-N(2)
S(1)-C(1)
[Å]
Bond angles
[Å]
2.2565(11)
2.3048(12)
1.407(5)
1.731(5)
P(1)-Au(1)-S(1)
C(1)-S(1)-Au(1)
C(9)-P(1)-Au(1)
177.83(4)
102.50(14)
114.54(14)
112.38(14)
111.61(13)
127.4(3)
C(15)-P(1)-Au(1)
C(21)-P(1)-Au(1)
N(1)-C(1)-S(1)
O(1)-C(1)-S(1)
4
c resulted in the largest Stokes shift with 113 nm in DMSO.
Compared with the difference of 66 nm in the maximum
fluorescence emission wavelength between the two states of 4b,
a showed an even larger red-shift of 85 nm in solution and in
120.2(3)
4
solid, which can be accredited to an increased non-radiative
decay due to increased intermolecular interactions caused by
2
.2. Photophysical properties
The UV-vis absorption spectroscopy of 4a, 4b and 4c were
[27-28]
aggregation.
We think, compared with the p-methyl
substituted benzene moiety in 4a, the o-hydroxy substituted
assessed in both DMSO solution (10 μM) and powder state. As
shown in Figure 2 and Table 3, the maximum absorption
wavelengths (λmax) of these complexes in DMSO solution were
benzene moiety in 4b is probably more successful in reducing the
[29]
intermolecular interaction in the aggregated state.
The
fluorescence lifetime of 4a and 4b in solid were shorter than that
in solutions, with one possible reason of the enhancement of
molecular interaction in the solid state, which shortened the
lifetime of excited state. (Table3)
2
98 nm (4a), 315 nm (4b), and 336 nm (4c), and in the powder
state, were 330 nm (4a), 335 nm (4b), and 348 nm (4c),
respectively. According to the previous literature reports[17], the
UV-vis absorption of these three compounds had been assigned
as follows: for 4a, the acromion at 276 nm was attributed to the
We found the solid fluorescence peak of 4b redshifted 9 nm,
compared with that in 4a, because of the enhancement of the
electron donor ability of the ligand substituents. The commission
international de l’eclairage (CIE) coordinates of 4a and 4b in the
powder state were proven to be in the green area with the values
being (0.26, 0.46) and (0.24, 0.41), respectively. Interestingly, 4c
has almost no fluorescence in the solid state. The possible reason
for that was the naphthalene ring in 4c showed strong π-π
accumulation effects, which lead to an obvious fluorescence
aggregation-caused quenching (ACQ) in solid state.
3
π-π* transition of PPh and the absorption peak at 298 nm was
attributed to intraligand (IL) transitions (oxadiazole derivatives)
and LMCT (S →Au); for 4b, the peaks of 270 nm and 277 nm
were attributed to the n-π* transition and the π-π* transition of
PPh , respectively. Meanwhile, the absorption at 291 nm of 4b
3
was attributed to IL (oxadiazole derivatives) and the one at 315
nm was assigned to LMCT (S →Au). The wide peak of 4c around
3
36 nm belonged to LMCT (S
→Au). The differences in the
positions of the UV absorption bands in the solution of these
three complexes came from the structural characteristics of the
aromatic nucleus present at the 5-position of 1, 3, 4-oxadiazole-2-
thiol and the related intramolecular charge-transfer between the
acceptor and the donor sites within the molecules. [24] With the
increase of electron donor capability of the aromatic nucleus, the
positions of maximum absorption peaks in 4a-4c appear obvious
redshift. (Figure 2a) Compared to the ones in solution, the
maximum absorption wavelengths (λmax) in the solid phases of 4a
and 4b were found red-shifted due to the molecular aggregation,
which therefore weakened the differences in the maximum
The results suggested that the fluorescence emission of these
gold (I) complexes can be adjusted by the introduction of
different substituent groups in 5-position in 1, 3, 4-oxadiazole-2-
thiol. The introduction of large heterocyclic structures with
strong electron donor capability will help to improve the
quantum yields. By reducing the size of the of the heterocyclic
structures, it may get new pure blue gold (I) complexes-based
luminescent materials. Therefore, this is of great significance for
the design of gold (I) complexes, that is, different optical
properties can be realized by introduction of various ligands to
suit for the future applications.
position of 4a-4b in the solid phase. [25] Band gaps (E
) of the
g
three complexes (solution/powder) were calculated to be 4a: 3.65
eV/3.25 eV, 4b: 3.72 eV/3.16 eV and 4c: 3.36 eV/3.09 eV, at the
[26]
onset (λonset) of the UV-Vis absorption spectrum. (Table 3)
Figure 2 ．UV-Vis absorption spectra of gold (I) phosphine complexes in
DMSO solution (10 μM) (a) and powder state (b). All spectrum data was
collected at room temperature.
The fluorescence behaviors of all the three complexes were
also investigated at the concentration of 10 μM in DMSO. (Fig
S41-S44) In solutions, the photoluminescence quantum yields
Figure 3. (a) Fluorescence emission spectra of 4a in different states; (b)
Fluorescence emission spectra of 4b in different states; (c) Fluorescence
emission and excitation spectra of 4c in DMSO; (d) CIE coordinates of
compounds in different states. The test concentration of all compounds is 10
μM in DMSO. All spectrum data was collected at room temperature.
(PLQY) of 4a (7.9 %), 4b (12.4 %) and 4c (18.3 %) increased
regularly with the increasing of structure rigidity: the hydrogen
bonding made 4b more rigid than 4a, and 4c with naphthyl
showed more rigid than 4b. The fluorescence emission of 4a and
Table 3. The photophysical and electrochemical properties of the 4a, 4b and 4c
a/b
LUMOa/b (eV)
a/b
c
States
λex(nm)
λem (nm)
Stokes
PLQY
Τ (ns)
HOMO (eV)
E
g
(eV)
g
E (eV)

4
Tetrahedron
shift (nm)
(%)
7.9
Solutions
Powders
Solutions
Powders
415
500
443
509
73
158
93
5.70
3.70
6.35
3.16
3.65
3.25
3.72
3.16
4
a
342
350
380
-6.79/-5.16
-6.67/-5.09
-6.24/-5.17
-3.78/-1.21
-3.79/-1.77
-3.62/-1.29
3.01/3.95
2.88/3.32
2.62/3.88
15.6
12.4
11.3
4
b
159
3
3
.36
.09
4
c
Solutions
493
113
18.3
3.63
aCalculated from cyclic voltammograms by formula HOMO = - (4.71 + Eox) (eV), LUMO = - (4.71 + Ered
bCalculated by Gaussian 09 software at the B3LYP/6-31G (d, p) level
)
cE
= 1240 / λonset ( λonset is the wavelength of the on-set of the UV-vis absorption spectrum)
g
λex : Maximum excitation wavelength; λem: Maximum emission wavelength; PLQY: Photoluminescence quantum yield; T: Fluorescence lifetime; Eg: Band gap
2
.3. Electrochemical and Thermal Properties
Cyclic voltammetry (CV) was performed with a traditional
three-electrode system to estimate the HOMO and LUMO energy
levels of the Au complexes 4a, 4b, and 4c. The oxidation peak
potentials of 4a, 4b, and 4c were found to be 2.08 V, 1.96 V, and
1
4
.53 V, respectively. The reduction peak potentials of 4a, 4b, and
c were found to be -0.93 V, -0.92 V, and -1.09 V, respectively
(
Figure 4). The HOMO and LUMO energy levels were calculated
[30]
according to the methods reported in the literature,
and the
data (HOMO /LUMO) obtained for these complexes were -6.79
eV / -3.78 eV (4a), -6.67 eV / -3.79 eV (4b), -6.24 eV / -3.62 eV
(
4c). (Table 3) The band gaps (Eg) of Au complexes determined
from electrochemical method (CV) and UV spectrum estimation
DMSO/solid) were 3.01 eV, 3.65 eV and 3.25 eV for 4a, 2.88
(
eV, 3.72 eV and 3.16 eV for 4b, and 2.62 eV, 3.36 eV and 3.09
eV for 4c, respectively. Compared with the LUMO level of the
[
31]
common electron-transport materials like BODIPY (-3.05 eV)
[32]
and Alq
transport because of its similar low LUMO level and band gap to
Alq . The most valuable output from this study, however, is that
3
(-3.0 eV) , 4c seems to be suitable for electron
3
the complexes 4a, 4b, and 4c have excellent thermal stability,
and their decomposition temperatures under nitrogen atmosphere
are 328.6 ℃, 329.9 ℃, and 318.9 ℃, respectively. (Figure 5)
Due to the good thermal stability and LUMO level, we think 4c
has the potential to be used as electron-transport materials in
OLEDs.
Figure 5. TG and DGT curve of 4a,4b and 4c
3
. Conclusions
We successfully synthesized three bidentate gold (I)
metalorganic complexes (4a, 4b, 4c) with 5-aromatic ring-1, 3, 4-
oxadiazole-2-thione and triphenylphosphine as ligands. The
structures of 4a and 4b were studied by single-crystal X-ray
diffraction. In solid-state, the CIE coordinates of 4a and 4b were
Figure 4. Cyclic voltammetry curves for 4a, 4b and 4c
(0.26, 0.46) and (0.24, 0.41) which belonged to the green area. 4a
showed the biggest E value according to the theoretical
g
calculations and 4c seems to be suitable for electron transport
2
.4. Theoretical calculations
because of its similar low LUMO level and band gap to Alq and
3
the good thermal stability. These results showed that the optical
Density functional calculations reveal that the band gaps of 4a,
b, and 4c are 3.95 eV, 3.32 eV, and 3.88 eV, respectively. (Fig
properties and energy levels of these gold (I) complexes were
affected by the substituents at 5-position in 1, 3, 4-oxadiazole-2-
thiol ligands. It indicated these complexes had the potential as
multifunctional materials to be used in emission or electron
transporting layers in OLEDs, which have important guiding
significance for future design of gold (I) complexes.
4
g
S46, Table 3) 4a showed the biggest E value, because of the
weak electron-donating group (–CH ), and the substituent effects
3
of 5-position in 1, 3, 4-oxadiazole-2-thiol were proven again in
the calculation results. It should be pointed out that the deviations
between the values obtained from theoretical calculation and the
experimental measurement results in solution may be attributed
to the limit of DFT calculation based on single-molecule in gas
state.
Acknowledgments

This work is supported by the National Natural Science
Foundation of China (No. 21672185, 22067019).
[13] Tang, M. C.; Lee, C. H.; Ng, M.; Wong, Y. C.; Chan, M. Y.;
Yam, V. W. Highly Emissive Fused Heterocyclic
Alkynylgold(III) Complexes for Multiple Color Emission
Spanning from Green to Red for Solution-Processable Organic
Light-Emitting Devices. Angew. Chem. Int. Ed. 2018, 57, 5463-
Supplementary Material
5
466.
The CCDC for 4a and 4b are 1885642 and 1891214,
respectively. The supporting information for this article,
including checkcif files, is available on the WWW under
https://doi.org/10.1016/j.tetlet.2020.xxxxxx.
[
14] Ghosh, B.; Febriansyah, B.; Harikesh, P. C.; Koh, T. M.;
Hadke, S.; Wong, L. H.; England, J.; Mhaisalkar, S. G.;
Mathews, N. Direct Band Gap Mixed-Valence Organic-
inorganic Gold Perovskite as Visible Light Absorbers. Chem.
Mater. 2020, 32, 6318-6325.
15] Tang, M.-C.; Kwok, W.-K.; Lai, S.-L.; Cheung, W.-L.; Chan,
M.-Y.; Wing-Wah Yam, V. Rational molecular design for
realizing high performance sky-blue-emitting gold(iii)
complexes with monoaryl auxiliary ligands and their
applications for both solution-processable and vacuum-
deposited organic light-emitting devices. Chemical Science
References
[
[1] Mora, M.; Gimeno, M. C.; Visbal, R. Recent advances in gold-
NHC complexes with biological properties. Chem. Soc. Rev.
2
019, 48, 447-462.
[
2] Wang, T.; Song, Y.; Jin, L.; Li, J.; Gao, Y.; Shi, S. Assembly of
Preformed Gold Nanoparticles onto Thermoresponsive Poly(N-
isopropylacrylamide)-Based Microgels on the Basis of Au-thiol
Chemistry. Chin. J. Chem. 2017, 35, 1755-1760.
2
019, 10, 594-605.
[
16] Tang, M.-C.; Li, L.-K.; Lai, S.-L.; Cheung, W.-L.; Ng, M.;
Wong, C.-Y.; Chan, M.-Y.; Yam, V. W.-W.； Design Strategy
Towards Horizontally Oriented Luminescent Tetradentate-
Ligand-Containing Gold(III) Systems.Angew Chem Int Ed
[
3] Zhang, M.; Di, X.; Zhang, M.; Zhang, J. Gold(I)-Catalyzed
Diastereo- and Enantioselective Synthesis of Polysubstituted
Pyrrolo[3,4-d][1,2]oxazines. Chin. J. Chem. 2018, 36, 519-525.
4] Kumar, R.; Nevado, C. Cyclometalated Gold(III) Complexes:
Synthesis, Reactivity, and Physicochemical Properties. Angew.
Chem. Int. Ed. 2017, 56, 1994-2015.
2
020, 59, 2-11.
[
[
17] Forward, J. M.; Bohmann D.; Fackler, J. P.; Staples, R. J.
Luminescence Studies of Gold(I) Thiolate Complexes. Inorg.
Chem. 1995, 34, 6330—6336.
18] Narayanaswamy, R.; Young, M. A.; Parkhurst, E.; Ouellette,
M.; Kerr, M. E.; Ho, D. M.; Elder, R. C.; Bruce, A. E.; Bruce,
M. R. M. Synthesis, Structure, and Electronic Spectroscopy of
Neutral, Dinuclear Gold(I) Complexes. Gold(I)-Gold(I)
Interactions in Solution and in the Solid State. Inorg. Chem.
[
5] Schmidt, C.; Karge, B.; Misgeld, R.; Prokop, A.; Franke, R.;
Brçnstrup, M.; Ott, I. Gold(I) NHC Complexes:
Antiproliferative Activity, Cellular Uptake, Inhibition of
Mammalian and Bacterial Thioredoxin Reductases, and Gram-
Positive Directed Antibacterial Effects. Chem. Eur. J. 2017, 23,
[
1
869 – 1880.
1
993, 32, 2506-2517.
[
[
6] Zhang, J.; Zhang, B.; Li, X.; Han, X.; Liu, R.; Fang, J. Small
[
19] Garcia, A.; Machado, R. C.; Grazul, R. M.; Lopes, M. T. P.;
Corrêa, C. C.; Dos Santos, H. F.; de Almeida, M. V.; Silva,
H.； Novel antitumor adamantane–azole gold(I) complexes
as potential inhibitors of thioredoxin reductase. J. Biol.
Inorg. Chem. 2016, 21, 275-292.
20] Chaves, J. D. S.; Tunes, L. G.; de, J. F. C. H.; Francisco, T. M.;
Correa, C. C.; Murta, S. M. F.; Monte-Neto, R. L.; Silva, H.;
Fontes, A. P. S.; de Almeida, M. V. Novel gold(I) complexes
with 5-phenyl-1,3,4-oxadiazole-2-thione and phosphine as
potential anticancer and antileishmanial agents. Eur. J. Med.
Chem. 2017, 127, 727-739
molecule inhibitors of mammalian thioredoxin reductase as
potential anticancer agents: An update. Med. Res. Rev. 2019,
3
9, 5-39.
7] Tong, K.-C.; Lok, C.-N.; Wan, P.-K.; Hu, D.; Fung, Y. M. E.;
Chang, X.-Y.; Huang, S.; Jiang, H.; Che, C.-M. An anticancer
gold(III)-activated porphyrin scaffold that covalently modifies
protein cysteine thiols. P. Natl. Acad. Sci. USA. 2020, 117,
[
1
321-1329.
[
8] Dennis, E. K.; Kim, J. H.; Parkin, S.; Awuah, S. G.; Garneau-
Tsodikova, S. Distorted Gold(I)–Phosphine Complexes as
Antifungal Agents. J. Med. Chem. 2020, 63, 2455-2469.
9] Yang, Y.; Antoni, P.; Zimmer, M.; Sekine, K.; Mulks, F. F.; Hu,
L.; Zhang, L.; Rudolph, M.; Rominger, F.; Hashmi, A. S. K.
Dual Gold/Silver Catalysis Involving Alkynylgold(III)
Intermediates Formed by Oxidative Addition and Silver-
Catalyzed C−H Activation for the Direct Alkynylation of
Cyclopropenes. Angew. Chem. Int. Ed. 2019, 58, 5129-5133.
10] Oki, Y.; Nakada, M. Research on Au (I)-catalyzed ene-yne
cycloisomerization for construction of quassinoid scaffold.
Tetrahedron Lett. 2018, 59, 926-929.
[
21] Hunks, W. J.; Jennings, M. C.; Puddephatt, R. J. Coordination
polymers of gold (I) with dithiolate and diphosphine ligands.
Chem. Commun. 2002, 1834-1835.
[
[
22] Ma, C.; Chan, C. T.; To, W. P.; Kwok, W. M.; Che, C. M.
Deciphering Photoluminescence Dynamics and Reactivity of
the Luminescent Metal-Metal-Bonded Excited State of a
Binuclear Gold (I) Phosphine Complex Containing Open
Coordination Sites. Chemistry 2015, 21, 13888-13893.
23] Tzeng, B.-C.; Chan, C.-K.; Cheung, K.-K.; Che, C.-M.; Peng,
S.-M. Dramatic solvent effect on the luminescence of a
dinuclear gold(I) complex of quinoline-8-thiolate. Chem
Commun. 1997, 135-136.
24] Cao, L.; Zhang, L.; Wei, Q.; Zhang, J.; Chen, D.; Wang, S.; Su,
S.-j.; Wang, T.; Ge, Z. Bipolar fluorophores based on
intramolecular charge-transfer moieties of sulfone for nondoped
deep blue solution-processed organic light-emitting diodes.
Dyes Pigments 2020, 176, 108242. https: // doi.org/ 10.1016/
j.dyepig.2020.108242
[
[
[
[
11] Zhou, D.; To, W. P.; Tong, G. S. M.; Cheng, G.; Du, L.;
Phillips, D. L.; Che, C. M. Tetradentate Gold (III) Complexes
as Thermally Activated Delayed Fluorescence (TADF)
Emitters: Microwave-Assisted Synthesis and High-Performance
OLEDs with Long Operational Lifetime. Angew. Chem. Int.
Ed. 2020, 59, 6375-6382.
[
12] Leung, M. Y.; Tang, M. C.; Cheung, W. L.; Lai, S. L.; Ng, M.;
Chan, M. Y.; Wing-Wah Yam, V. Thermally Stimulated
Delayed Phosphorescence (TSDP)-Based Gold(III) Complexes
of Tridentate Pyrazine-Containing Pincer Ligand with Wide
Emission Color Tunability and Their Application in Organic
Light-Emitting Devices. J. Am. Chem. Soc. 2020, 142, 2448-
[
25] Noginov, M. A.; Vondrova, M.; Williams, S. M.; Bahoura, M.;
Gavrilenko, V. I.; Black, S. M.; Drachev, V. P.; Shalaev, V. M.;
Sykes, A. Spectroscopic studies of liquid solutions of R6G laser
dye and Ag nanoparticle aggregates. J. Opt. A-Pure Appl. Op.
2
459.
2
005, 7, S219-S229.

6
Tetrahedron
[26]
Song, Q.; Li, F.; Wang, Z.; Zhang, X. A supramolecular
Photoluminescence, and Electrochemistry Properties. J. Org.
Chem. 2008, 73, 1571-1574.
strategy for tuning the energy level of naphthalenediimide:
Promoted formation of radical anions with extraordinary
stability. Chem. Sci. 2015, 6, 3342-3346.
[32] Burrows, P. E.; Shen, Z.; Bulovic, V.; McCarty, D. M.; Forrest,
S. R.; Cronin, J. A.; Thompson, M. E. Relationship between
electroluminescence and current transport in organic
heterojunction light‐emitting devices. J. Appl. Phys. 1996, 79,
7991-8006.
[
27] Ouyang, X.; Wang, G.; Zeng, H.; Zhang, W.; Li, J. Design and
synthesis of 2-substituted-8-hydroxyquinline zinc complexes
with hole-transporting ability for highly effective yellow-light
emitters. J. Organomet. Chem. 2009, 694, 3511-3517.
[
[
[
28] Yam, V. W.-W.; Cheng, E. C.-C. Design of luminescent sulfur-
containing polynuclear gold (I) complexes for advanced
nanomaterials and chemosensors.Gold Bulletin 2001, 34, 20-23.
29] Forward, J. M.; Bohmann, D.; Fackler, J. P.; Staples, R. J.
Luminescence Studies of Gold(I) Thiolate Complexes. Inorg.
Chem. 1995, 34, 6330-6336.
30] Dong, Y.-B.; Chen, Z.; Yang, L.; Hu, Y.-X.; Wang, X.-Y.; Yin,
J.; Liu, S. H. Effect of alkyl chain length on the luminescence
on-off mechanochromic behavior of solid-state Gold(I)
isocyanide complexes. Dyes Pigments. 2018, 150, 315-322.
31] Zhou, Y.; Xiao, Y.; Li, D.; Fu, M.; Qian, X. Novel Fluorescent
Fluorine−Boron Complexes:ꢀSynthesis, Crystal Structure,
Graphical Abstract
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Leave this area blank for
abstract info.
New gold (I) complexes with 5-aromatic ring-1, 3, 4-oxadiazole-2-thione and
triphenylphosphine as potential multifunctional materials
Yu Qiang Zhao, Jie Zhou, Renze He, Guang Ke Wang, Lan Xi Miao, Xiao Guang Xie and Ying Zhou*
Three new gold (I) complexes (4a, 4b, 4c) with 5-aromatic ring-1, 3, 4-oxadiazole-2-thione and
triphenylphosphine as ligands were synthesized. Structures of 4a and 4b were determined through X-ray single-
crystal diffraction, and it displayed that 4a and 4b had the same metal coordination pattern, wherein the ligand
was coordinated by the sulfur atom to the central metal ion of gold (I). The optical properties of these gold (I)
complexes were studied both in solution and in solid-state. In DMSO, 4a and 4b peaked at 415 nm and 443 nm,
respectively, and the CIE coordinates of 4a and 4b in the solid-state were in the green area namely, (0.26, 0.46)
and (0.24, 0.41). HOMO/LUMO levels and bandgaps of 4a, 4b and 4c were assessed by UV spectrum estimation,
electrochemical method, and theoretical calculations. The observation hinted that the photophysical properties
and energy levels of these gold (I) complexes can be adjusted by the introduction of different substituent aromatic
rings at the 5-position of the 1, 3, 4-oxadiazole-2-thiol moiety. The findings of good optical, electrochemical and
thermal properties of these new gold (I) complexes demonstrated their potential in the future studies as
multifunctional materials.

●
Gold (I) complexes with 5-aromatic ring-1, 3, 4-
oxadiazole-2-thione were synthesized.
Structures of 4a and 4b were determined
through X-ray single-crystal diffraction.
These new gold (I) complexes showed good
optical, electrochemical and thermal properties.
These new gold (I) complexes demonstrated
●
●
●
their potential in the future studies as
multifunctional materials.