Different structures modulated mechanochromism and aggregation-induced emission in a series of Gold(I) complexes

Article abstract of DOI:10.1016/j.dyepig.2018.03.062

Five novel gold(I) complexes with various isocyanide ligands have been synthesized and characterized in present work. The introduction of different terminal ligands endows distinct diverse properties to complexes 1–5: i) alkyl modified complexes 1–3 exhibit tricolor or bicolor mechanochromic behaviors due to the loosing packing formed through weak intermolecular C–H···F interactions, while aryl bridged complexes 4 and 5 are not mechano-responsive with tight π-π stackings; ii) all the target complexes present prominent but different aggregation-induced emission(AIE) characteristics caused by the inherent difference in their structures. Therefore, the above gold(I) complexes are anticipated to be used as fluorescent detectors and mechanosensors.

Full text of DOI:10.1016/j.dyepig.2018.03.062

Accepted Manuscript
Different structures modulated mechanochromism and aggregation-induced emission
in a series of Gold(I) complexes
Xiao-Yan Wang, Jing Zhang, Yu-Bao Dong, Yiyue Zhang, Jun Yin, Sheng Hua Liu
PII:
S0143-7208(18)30472-8
10.1016/j.dyepig.2018.03.062
DYPI 6647
DOI:
Reference:
To appear in: Dyes and Pigments
Received Date: 2 March 2018
Revised Date: 26 March 2018
Accepted Date: 26 March 2018
Please cite this article as: Wang X-Y, Zhang J, Dong Y-B, Zhang Y, Yin J, Liu SH, Different structures
modulated mechanochromism and aggregation-induced emission in a series of Gold(I) complexes, Dyes
and Pigments (2018), doi: 10.1016/j.dyepig.2018.03.062.
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to
our customers we are providing this early version of the manuscript. The manuscript will undergo
copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please
note that during the production process errors may be discovered which could affect the content, and all
legal disclaimers that apply to the journal pertain.

ACCEPTED MANUSCRIPT
Different Structures Modulated Mechanochromism and
Aggregation-induced Emission in a series of Gold(I) Complexes
a,‡
a,‡
a
a
a,
Xiao-Yan Wang , Jing Zhang , Yu-Bao Dong , Yiyue Zhang , Jun Yin *, Sheng
a,b,
Hua Liu *
Graphical Abstract
Five novel gold(I) complexes with distinct diverse (bicolor or tricolor) switching
mechanochromic and prominent AIE properties have been reported in present work.
Abnormally, the e- and a-conformers coexisted in the same crystal unit cell for
mono-substituted cyclohexyl Au(I) complex, which is quite rare in the similar gold
systems. The five newly-developed(I) complexes are anticipated to be used as
fluorescent detector and mechanosensors.

ACCEPTED MANUSCRIPT
1
2
Different Structures Modulated Mechanochromism and
Aggregation-induced Emission in a series of Gold(I) Complexes
a,‡
a,‡
a
a
a,
3
4
Xiao-Yan Wang , Jing Zhang , Yu-Bao Dong , Yiyue Zhang , Jun Yin *, Sheng Hua
a,b,
Liu *
a
5
6
Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, College of
Chemistry, Central China Normal University, Wuhan 430079, PR China
b
7
8
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the
Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, PR China
9
0
1
2
‡ These authors contributed equally to this work.
1
1
1
Tel: +86-27-67867725
Fax: +86-27-67867725
Corresponding author E-mail: yinj@mail.ccnu.edu.cn, chshliu@mail.ccnu.edu.cn
13
ABSTRACT
14
15
16
17
Five novel gold(I) complexes with various isocyanide ligands have been synthesized and
characterized in present work. The introduction of different terminal ligands endows
distinct diverse properties to complexes 1-5: i) alkyl modified complexes 1-3 exhibit
tricolor or bicolor mechanochromic behaviors due to the loosing packing formed through

ACCEPTED MANUSCRIPT
18
19
20
21
22
weak intermolecular C–H···F interactions, while aryl bridged complexes 4 and 5 are not
mechano-responsive with tight π-π stackings; ii) all the target complexes present
prominent but different aggregation-induced emission(AIE) characteristics caused by the
inherent difference in their structures. Therefore, the above gold(I) complexes are
anticipated to be used as fluorescent detectors and mechanosensors.
2
3
4
Key words: Gold(I)-isocyanide complexes; Mechanochromism; Aggregation-induced
2
emission(AIE); Crystal structures
25
1. Introduction
26
27
28
29
30
31
32
33
34
35
36
37
Smart materials refer to the materials that can make response upon external (optical,
electrical, thermal, solvent, anions, mechanical, etc.) stimulation [1-6].
Mechanical-responsive luminescent materials, as one of quintessential representatives of
smart materials, have attracted increasing attention because of their extensive
applications in optoelectronic devices [7], storage and memories fields [8], mechanical
sensors [6], and chemical detectors [9]. The solid-state luminance of mechanochromic
materials usually exhibit reversible or irreversible turn-on switching [4], or turn-off
switching [5] involving two-color transformation [6], or even multicolor tunning [7, 10]
under the stimuli of mechanical force (press, shear, stretch, grind, etc [6, 7,10-11]).
Among them, metal complexes based on Pt(II) [13-15], Ir(III) [16-18], and Cu(I) [19-21]
constitute a significant portion, while the newly-developed systems associated with Au(I)
are still limited in recent years [22-26]. In 2008, the first gold(I) complex that exhibits

ACCEPTED MANUSCRIPT
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
blue-to-yellow emission conversion upon grinding with pestle was reported by Ito and
co-workers [22]. The related research results indicate that intermolecular aurophilic
interactions may be the main reason for the emission change upon mechanic stimulation.
However, multicolor mediated mechanochromic materials are very rare, let alone the
capture of the unstable intermediate state before recovering to initial state [27].
In the meanwhile, the development of luminogens with aggregation-induced
emission characteristic (AIEgens) has been in a boiling state since the discovery of
abnormal AIE phenomenon by Tang’s group in 2001 [28]. So far, a great number of gold
complexes with AIE or mechanochromic properties have been reported [29-38]. In our
previous work, we also developed a series of gold(I)-isocyanide complexes exhibiting
outstanding AIE and mechanochromic behaviors [24, 25, 39], in which the Au–C≡N
coordination bonds are linear or approximately linear similar to the other reported gold(I)
isocyanide complexes. In this paper, we reported five novel gold(I) complexes with
different isocyanide ligands (Figure 1) and investigated thoroughly the effect of terminal
ligands on photophysical properties of these gold(I) complexes. In addition, we observed
some significant conformations according to our following crystal analysis. The above
special structural characteristics may endow these systems distinct photophysical
properties.
Insert Figure 1

ACCEPTED MANUSCRIPT
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
2. Experiments
2.1. Materials and methods
Specific synthetic strategy has been demonstrated in Scheme 1. All manipulations
were carried out under an argon atmosphere by using standard Schlenk techniques,
unless otherwise stated. The starting material isocyanide 1a
purchased from Alfa Aesar and were used directly. CH Cl was dried with CaH
2
, 2a, 3a, 4a were
2
2
then distilled, and ultra-pure water was used in the experiments. All other starting
materials and reagents were obtained commercially from Shen Shi Hua Gong
1
Company (China) as analytical-grade and used without further purification. H
13
NMR and C NMR spectra were collected on American Varian Mercury Plus 400
spectrometer (400 MHz), Bruker AVANCE III HD-400 or Varian MERCURY Plus
1
600 MHz instrument. H NMR spectra are reported as followed: chemical shift in
ppm (δ) relative to the chemical shift of TMS at 0.00 ppm, integration, multiplicities
13
(s = singlet, d = doublet, t = triplet, m = multiplet), and coupling constant (Hz). C
NMR chemical shifts reported in ppm (δ) relative to the central line of triplet for
19
3 6 6
CDCl at 77 ppm. F NMR chemical shifts are relative to C F (δ = -163.00). EI-MS
was obtained using Thermo scientific DSQⅡ . Elemental analyses (C, H, N) were
performed by the Microanalytical Services, College of Chemistry, CCNU. UV-Vis
spectra were obtained on Shimadzu UV-3600 spectrophotometer. Fluorescence
spectra were recorded on a Hitachi-F-4500 fluorescence spectrophotometer and
Fluoromax-P luminescence spectrometer (HORIBA JOBIN YVON INC.) Absolute

ACCEPTED MANUSCRIPT
78
79
80
81
82
83
84
85
fluorescence quantum yields were measured on a Hamamatsu C11347 Absolute PL
quantum yield spectrometer. XRD studies were recorded on a Shimadzu XRD-6000
diffractometer using Ni-filtered and graphite-monochromated Cu Kα radiation (λ =
1.54 Å, 40 kV, 30 mA). The X-ray crystal-structure data were obtained by the
Bruker APEX DUO CCD system. DFT calculations were performed with the
Gaussian 09 program at the B3LYP/6-31G* (Au: Lanl2DZ) level of theory.
2.2. Synthesis
2.2.1. General procedure for the synthesis of 4b-4c
86
87
88
89
90
91
92
93
Compounds 4b, 4c, Au(C F )(tht) (tht = tetrahydrothiophene) were prepared
6
5
1
according to the corresponding literatures [40-42]. 4b: Yield: 73%. H NMR (600 MHz,
6
DMSO-d ): δ (ppm) = 10.31 (s, 1H, CHO), 8.48 (s, 1H, NH), 8.13 (d, J = 8.4 Hz, 1H,
Ar-H), 8.07-7.86 (m, 2H, Ar-H), 7.76 (m, 1H, Ar-H), 7.52 (d, J = 47.2 Hz, 3H, Ar-H).
+
+
1
EI-MS: m/z = 171.2 [M] ; Found: m/z = 171.2 [M] . 4c: Yield: 50%. H NMR (400
MHz, CDCl ): δ (ppm) = 8.19 (d, J = 8.4 Hz, 1H, Ar-H), 7.89 (d, J = 8.4 Hz, 2H, Ar-H),
3
7.67 (d, J = 8.3 Hz, 1H, Ar-H), 7.58-7.62 (m, 2H, Ar-H), 7.44 (d, J = 8.2 Hz, 1H, Ar-H).
+
+
EI-MS: m/z = 153.2 [M] ; Found: m/z = 153.3 [M] .
94
2.2.2. General procedure for the synthesis of 5b-5d
95
96
97
Syntheses of compounds 5b and 5c: The mixture of 5a (0.50 g，2.60 mmol) and
K CO (1.10 g, 7.80 mmol) was added in DMF (30 ml). And 1-bromodecane (0.69 g,
2
3
3.10 mmol) was added dropwise after heating to reflow temperature and the reaction

ACCEPTED MANUSCRIPT
9
8
9
2 2
solution was refluxed for 12 hours. Then the reaction system was extracted with CH Cl
9
(3×20 mL). The combined organic layer was dried over anhydrous magnesium sulfate,
filtered and concentrated under reduced pressure to afford a deep purple oily liquid. The
residue was stirred for 12 h at 110 Ⅱ with formic acid (30 ml). After a series of
1
1
1
1
1
1
1
1
1
00
01
02
03
04
05
06
07
08
1
post-processing, collecting the expected purple solid 0.41 g of 5c in a yield of 48%. H
NMR (400 MHz, CDCl ): δ (ppm) = 8.41 (d, J = 11.5 Hz, 0.5 H, CHO, cis), 8.34 (d, J =
3
8.2 Hz, 0.5 H, CHO, trans), 7.90 (d, J = 8.3 Hz, 0.5 H, NH, trans), 7.72-7.81 (dd, J = 8.3
Hz, 0.5 H, NH, cis), 7.61 (d, J = 8.5 Hz, 1H, Ar-H), 7.56 (t, J = 13.5 Hz, 1H, Ar-H), 7.26
(d, J = 8.2 Hz, 1H, Ar-H), 7.23 (d, J = 8.1 Hz, 1H, Ar-H), 6.78 (d, J = 8.1 Hz, 2H, Ar-H),
4.14 (t, J = 6.3 Hz, 2H, OCH ), 1.93 (d, J = 6.9 Hz, 4H, CH ), 1.35 (s, 12H, CH ), 0.88 (t,
2
2
2
+
+
J = 6.5 Hz, 3H, CH ). EI-MS: m/z = 327.5 [M] ; Found: m/z = 327.3 [M] .
3
1
1
1
1
1
1
1
09
10
11
12
13
14
15
Synthesis of compound 5d: The procedure of 5d is similar to compound 4c using the
following amounts: 5c (1.00 g, 5.80 mmol) and triphosgene (1.89 g, 6.40 mmol). The
1
product was obtained as a deep purple solid (0.42 g) in a yield of 64%. H NMR (400
MHz, CDCl ): δ (ppm) = 8.32 (d, J = 8.3 Hz, 1H, Ar-H), 8.12 (d, J = 8.1 Hz, 1H, Ar-H),
3
7.68 (t, J = 7.6 Hz, 1H, Ar-H), 7.60 - 7.51 (m, 2H, Ar-H), 6.72 (d, J = 8.2 Hz, 1H, Ar-H),
4.16 (t, J = 6.4 Hz, 2H, OCH
2
), 2.22 - 1.94 (m, 4H, CH
2
2
), 1.27 (d, J = 9.3 Hz, 12H, CH ),
+
+
0.88 (t, J = 7.0 Hz, 3H, CH
3
). EI-MS: m/z = 309.5 [M] ; Found: m/z = 309.6 [M] .
1
16
2.2.3. General procedure for the synthesis of 1-5

ACCEPTED MANUSCRIPT
1
1
1
1
1
1
1
1
1
17
18
19
20
21
22
23
24
25
6 5
Synthesis of complex 1: Under an argon atmosphere, a mixture of C F Au(tht) (0.41
2 2
g, 0.91 mmol) and 1a (0.074 g, 0.88 mmol) was stirred in CH Cl (20 ml) overnight at
room temperature. After finishing the present reaction, the reaction system was
concentrated in vacuo. Recrystallization with CH Cl /n-hexane. The product was
2
2
1
obtained as a light-yellow solid (0.20 g, 52%). H NMR (400 MHz, CDCl ): δ (ppm) =
3
1
3
1.61 (s, 9H, CH ). C NMR (100 MHz, CDCl ): δ (ppm) = 150.5, 148.5, 140.5, 138.1,
3
3
19
135.7, 58.7, 29.7. F NMR (CDCl ): δ (ppm) = -116.1, -157.9, -162.8. IR (KBr): 2219
3
-1
ν(C≡N) cm . Anal. Calcd for C H AuF N: C, 29.55; H, 2.03; N, 3.13. Found: C, 29.34;
11
9
5
H, 2.13; N, 3.09.
1
1
1
1
1
1
1
1
26
27
28
29
30
31
32
33
Synthesis of complex 2: The procedure of complex 2 is similar to complex 1 using
the following amounts: C F Au(tht) (0.46 g, 1.03 mmol) and 2a (0.11 g, 1.00 mmol).
6
5
1
The product was obtained as a white solid product (0.47 g, 46%). H NMR (400 MHz,
CDCl ): δ (ppm) = 3.89 (s, 1H, NCH), 2.03 (s, 2H, CH ), 1.81 (s, 4H, CH ), 1.48 (s, 4H,
3
2
2
13
CH ). C NMR (100 MHz, CDCl ): δ (ppm) = 150.7, 149.1, 148.2, 140. 5, 138.0, 135.6,
2
3
19
128.4, 54.7, 31.6, 24.6, 22.7. F NMR (CDCl ): δ (ppm) = -115.9, -158.1, -162.7. IR
3
-1
(KBr): 2217 ν(C≡N) cm . Anal. Calcd for C H AuF N: C, 33.00; H, 2.34; N, 2.96.
1
3
11
5
Found: C, 32.88; H, 2.42; N, 2.90.
1
1
1
34
35
36
Synthesis of complex 3: The procedure of complex 3 is similar to complex 1 using
the following amounts: C F Au(tht) (0.46 g, 1.03 mmol) and 3a (0.13 g, 1.00 mmol). The
6
5
1
product was obtained as a white solid (0.27 g, 56%). H NMR (400 MHz, CDCl ): δ
3

ACCEPTED MANUSCRIPT
1
1
1
1
1
37
38
39
40
41
(ppm) = 7.36 (t, J = 7.7 Hz, 1H, Ar-H), 7.19 (d, J = 7.7 Hz, 2H, Ar-H), 2.50 (s, 6H,
1
3
Ar-CH
3
). C NMR (100 MHz, CDCl
3
): δ (ppm) = 161.0, 150.5, 148.2, 140.6, 138.1,
): δ (ppm) = -116.0, -157.5, -162.5. IR
(KBr): 2220 ν(C≡N) cm . Anal. Calcd for C H AuF N: C, 36.38; H, 1.83; N, 2.83.
1
9
136.2, 131.0, 128.5, 124.1, 18.7. F NMR (CDCl
3
-1
1
5
9
5
Found: C, 36.27; H, 1.91; N, 2.76.
1
1
1
1
1
1
1
1
42
43
44
45
46
47
48
49
Synthesis of complex 4: The synthesis of complex 4 is similar to complex 1 using
the following amounts: C
6
F
5
Au(tht) (0.29 g, 0.44 mmol) and 4c (0.07 g, 0.43 mmol). The
1
product was obtained as a white solid (0.13 g, 58%). H NMR (400 MHz, CDCl ): δ
3
(ppm) = 8.12 (t, J = 9.0 Hz, 2H, Ar-H), 8.00 (d, J = 7.9 Hz, 1H, Ar-H), 7.85 - 7.75 (m,
1
3
2H, Ar-H), 7.71 (t, J = 7.1 Hz, 1H, Ar-H), 7.57 (t, J = 8.4 Hz, 1H, Ar-H). C NMR (100
MHz, CDCl ): δ (ppm) = 133.6, 132.3, 129.2, 128.9, 128.3, 127.7, 126.2, 125.0, 121.9.
3
1
9
-1
F NMR (CDCl ): δ (ppm) = -116.0, -157.3, -162.3. IR (KBr): 2220 ν(C≡N) cm . Anal.
3
Calcd for C H AuF N: C, 39.48; H, 1.36; N, 2.71. Found: C, 39.35; H, 1.45; N, 2.65.
1
7
7
5
1
1
1
1
1
1
1
50
51
52
53
54
55
56
Synthesis of complex 5: The procedure of 5 is similar to complex 1 with
C F Au(tht) (0.20 g, 0.45 mmol) and 5d (0.14 g, 0.44 mmol). The product was obtained
6
5
1
as a white solid (0.19 g, 65%). H NMR (400 MHz, CDCl ): δ (ppm) = 8.39 (d, J = 9.0
3
Hz, 1H, Ar-H), 8.03 (d, J = 8.4 Hz, 1H, Ar-H), 7.83-7.70 (m, 2H, Ar-H), 7.65 (t, J = 7.7
Hz, 1H, Ar-H), 6.80 (d, J = 8.4 Hz, 1H, Ar-H), 4.21 (t, J = 6.4 Hz, 2H, OCH ), 2.03 -
2
1
3
1.90 (m, 2H, CH ), 1.46 - 1.18 (m, 14H, CH ), 0.89 (t, J = 7.0 Hz, 3H, CH ). C NMR
2
2
3
(100 MHz, CDCl ): δ (ppm) = 159.6, 158.0, 150.8, 148.5, 140.6, 138.2, 135.7, 129.4,
3

ACCEPTED MANUSCRIPT
1
1
1
1
57
58
59
60
128.7, 127.5, 125.6, 123.3, 121.7, 113.0, 103.6, 69.2, 31.9, 29.6, 29.3, 29.0, 26.2, 22.7,
1
9
-1
14.1. F NMR (CDCl
3
): δ (ppm) = -116.0, -157.6, -162.4. IR (KBr): 2222 ν(C≡N) cm .
Anal. Calcd for C27
1.99.
H27AuF NO: C, 48.15; H, 4.04; N, 2.08. Found: C, 48.03; H, 4.11; N,
5
1
61
Insert Scheme 1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
3. Results and discussion
3.1. Synthesis
The synthetic route of complexes 1-5 has been presented in Scheme 1. These five
target gold(I) complexes were obtained in a few steps with the yields of 46%-65%.
3.2. Diverse mechanochromic properties of 1-3
Mechanochromic properties were investigated by means of photoluminescence (PL)
spectroscopy. Complex 1 exhibited a “turn-on” and tricolor change in response to the
external mechanical stimuli. As shown in Figure 2, the initial powder of complex 1
exhibited a weak emission at 465 nm, which is hard to be observed under the irradiation
of 365 nm UV lamp due to a low quantum yield (Ф ) of 3.7%. But its emission could be
F
further lighted up by the stimulation of mechanical force, showing bright cyan
luminescence with a red-shifted band at 495 nm, and the corresponding quantum yield
was increased by 6.5-fold (Ф = 24.2%). Interestingly, unlike some similar reported
F
mechanochromic systems [43], in which the emission of ground powder could revert to
the original state very directly after exposing to dichloromethane vapor, yet the cyan

ACCEPTED MANUSCRIPT
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
fluorescence of complex 1 transformed into dark yellow after fuming showing a broad
band at around 560 nm. The above transformation between the yellow transition state and
the cyan state is reversible, while the original blue state could not be recovered.
Regarding complex 2, a reversible color change from blue (
λem,max= 466 nm) to cyan
(λem,max= 484 nm) was discovered upon grinding with an obviously increased quantum
yield from 6.3% to 10.9%. Interestingly, we observed that the above cyan powder need
go through an orange transition state before recovering to the initial blue state after
fuming with dichloromethane vapor. Subsequently, this metastable state self-recovered to
the original state within a few minutes without any treatment and this self-recovery
process showed desirable repeatability. Unfortunately, this special state was too
instantaneous to be further explored. In the case of complex 3, a reversible transformation
from an original blue emission (Ф = 27.7%) to a brighter cyan state (Ф = 61.3%) could
F
F
also be realized by mechanical grinding and dichloromethane fuming. Accordingly,
complex 3 showed a typical bicolor switching mechanochromic behavior. The detailed
mechanochromic data of complexes 1-3 have been summarized in Table 1. Indeed, no
any obvious emission change could be observed upon mechanical stimulation for
complexes 4 and 5. This might be caused by the existence of strong intermolecular
interactions and hence formed compact packings due to the presence of naphthalene rings
(vide infra), which is difficult to destroyed under the stimulation of external mechanical
forces.
Insert Table 1

ACCEPTED MANUSCRIPT
1
1
98
99
Insert Figure 2
Insert Figure 3
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
To further explore the mechanochromic mechanism, the changes of molecular
arrangements in different states were investigated via powder X-ray diffraction (XRD).
As shown in Figure 2, Figure S4 and S5, the XRD patterns of the initial solid samples for
complexes 1–3 all exhibited sharp and intense peaks consistent with the diffraction peaks
obtained by single crystal structure simulation, indicating that all the original states are
crystalline states. After grinding with pestle, weak and broadening peaks were observed
for these three complexes, corresponding to the formation of amorphous phases.
Differently, some new ordered intense diffraction peaks differing from the initial pattern
2 2
appeared in complex 1 after treating the ground samples with CH Cl vapor. The above
observations demonstrate that the crystalline phase after fuming is different from that of
unground sample and diverse morphologies give rise to various fluorescence. This may
be the reason why complex 1 exhibits tricolor-changing mechanochromic behavior.
While the reflection peaks of fumed sample could be restored for complex 2 and 3. It
explained reversible bicolor but not tricolor mechanochromism for complex 2 and 3.
Anyway, we can preliminarily conclude that the reversible conversions between
crystalline states and amorphous phases are responsible for the above color changes for
complexes 1–3 upon mechanical stimulation.
3.3. Crystal structures and DFT calculations

ACCEPTED MANUSCRIPT
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
Furthermore, we look forward to setting up deep understanding of the
aforementioned mechanochrmic behaviors. Fortunately, we obtained the crystal
2 2
structures for all the target complexes 1–5 by slow crystallization from CH Cl /MeOH
or hexane. Accordingly, we carried out detailed exploration for the above crystal
structures and anticipated to unearth some interesting information. Pertinent diffraction
parameters, bond lengths (Å) and bond angles (deg) have been presented in Table S1-S6
(ESI†). By comparing the above crystal data, we can observe that the whole molecular
skeletons of complexes 1 and 3 feature desirable coplanar and linear structure with the
Au–C≡N and C–Au–C angles of 180.00°. The structure of complex 5 is approximately
linear with the Au–C≡N angle of 178.09° and C–Au–C angle of 179.73°, respectively
(Figure S6). The characters of the above complexes are very similar to the systems
reported in literatures [6, 12, 22, 23]. In addition, the nearly linear Au–C≡N
(e-conformer: 179.57°; a-conformer: 176.93°) and C–Au–C (e-conformer: 176.37°;
a-conformer: 173.92°) angles in these two conformers show slightly difference for
complex 2. Specifically, complex 4 exhibits bent structures with the Au–C≡N and
C–Au–C angles of 164.57° and 173.64°, respectively (Figure 5). It should be mentioned
that the above bending conformation is still rarely observed in the reported
gold(I)-isocyanide systems [6, 12, 23]. Mono-substituted cyclohexyl undergo rapid
chair-to-chair conversion between two different conformations, viz. equatorial (e-) and
axial (a-) conformers, at room temperature [44]. It has been documented that the
equatorial conformer is ordinarily more stable when the substituent is a bulky group due

ACCEPTED MANUSCRIPT
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
to the steric effects. However, we observed both the e- and a-conformers in the same unit
cell for complex 2, with the isocyano–Au segment located in the equatorial and axial sites
on the cyclohexyl ring, respectively (Figure 4). More interestingly, the two conformers
are oriented in opposite directions and weak C–H···F interactions could be observed
between different conformers. In 2005, Balch et al. also reported a similar [(cyclohexyl
I
isocyanide) Au ](PF ) complex and they obtained the yellow and colorless forms of
2
6
polymorphs successfully, in which the colorless polymorph consists of two half-cations
with the e- and a-conformer, respectively [45]. In order to get insight into the above
phenomenon, we carried out the density functional theory (DFT) calculations based on
the monomer (e- and a-conformer) and dimer models using the B3LYP functional. The
basis set employed here is 6-31G* (Lanl2DZ for Au atom). As shown in Figure 6, the
HOMO and LUMO orbitals of both e- and a-conformers predominantly localize on the
C6F5 unit and the central isocyano-Au fragment, respectively, indicating an
intramolecular ligand to metal charge transfer transition character, while the two
monomers separately contribute to the frontier molecular orbital for the dimer and an
obvious intermolecular charge transfer could occur. In addition, the energies of HOMO
(e-: -6.06, a-: -6.08 eV) and LUMO (e-: -1.29 eV, a-: -1.36 eV) orbitals for both e- and
a-conformers are very similar. But their respective energy gap (-4.7 eV) is obviously
higher than that of the dimer (-4.3 eV). These results imply that the intermolecular charge
transfer is much easier to occur than that of the intramolecular process, which might
provide a good foundation for the stable coexistence of both two conformers.

ACCEPTED MANUSCRIPT
2
2
2
60
61
62
Insert Figure 4
Insert Figure 5
Insert Figure 6
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
We are then interested in exploring the crystal packing of complexes 1–5 and
attempt to find the reason for their different mechanochromic behaviors. Complexes 1-3
only feature multiple intermolecular C–H···F interactions formed by head-to-tail
arrangement between the terminal penta-fluorophenyl group and the adjacent alkyl or
aryl group, respectively, except for complex 3 interacting with disordered methanol
molecule. And these multiple intermolecular C–H···F interactions act as guiding force
and hold the molecules to form loose 3D networks for complexes 1-3. The slippage is
very likely to take place between molecules under the stimulus of external mechanical
force and the intermolecular distances containing gold-gold distances could be perturbed,
which is supported by an obvious red shift in their respective emission peak after
grinding. By contrast, the distances between the centers of intermolecular aryl rings for
complexes 4 and 5 are 3.467Å and 3.472Å, respectively. It’s clear that complexes 4 and 5
exhibited strong intermolecular π-π interactions due to the presence of naphthalene rings
and presented very tight stackings, which brings out that the corresponding packing
modes for complexes 4 and 5 are hard to change by grinding and complexes 4 and 5
accordingly do not show mechanochromic behaviors. In addition, based on the different
crystal packings of complexes 4 and 5, it’s also clear that the introduction of a simple

ACCEPTED MANUSCRIPT
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
alkoxy group could effectively tune the crystal structures. Herein, our original
expectation of achieving distinct diverse properties by a simple modification for the
bridging ligands of a series of gold complexes might be fulfilled successfully.
3.4. AIE behaviors
Based on the preceding mechanochromic investigation, we observed that all the
solid states for complexes 1–5 were luminescent, although their corresponding emission
intensities were not very remarkable. However, when we turned to explore their
corresponding solution states, we found that all the complexes were not luminescent,
which inspired us to associate with the AIE phenomenon. Therefore, using THF as a
good solvent and water as a poor solvent, we measured the UV-vis absorption spectra and
photoluminescence of complexes 1–5 in THF/H O mixtures with various water fractions
2
(fw). The corresponding data is listed in Table 2. As shown in Table 2, all the complexes
presented absorption peaks from 200-350 nm, which could be contributed to the π-π*
transitions. On the other hand, the absorption evidently broadened and exhibited
distinctly various degree of red-shift when the water volumes were increased to a certain
value. At the same time, obvious level-off tails were also observed at long-wavelength
region, which might result from the presence of real nano-aggregates [46-47]. The
formation of aggregates was confirmed by DLS (Dynamic Light Scattering) study and the
related data have been showed in Figure S11.
Insert Table 2

ACCEPTED MANUSCRIPT
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
Emission spectra demonstrated that their respective aggregation processes would be
lighted when the poor solvents were added to the solution. Complexes 1 (tert-butyl
substituted) and 2 (cyclohexyl substituted) exhibited typical AIE behavior, which
displayed continually increased luminescence during the aggregation process. Complex 1
presented one weak emission band with λmax at around 375 nm in pure THF. However,
the original emission intensity decreased and a new broad peak at 500–600 nm appeared
exhibiting yellow emission when the water fraction was increased to 90%. The
corresponding emission intensity boosted markedly over 20-times compared with it being
in pure THF. A similar AIE phenomenon was observed for complex 2. The original weak
emission in pure THF solution was around 408 nm and further aggregation induced
emission appeared at around 557 nm, and equally raising f gave rise to dramatic increase
w
of the emission intensity over than 40-times. Actually, this is because that these
complexes are soluble in THF solution but practically immiscible with water. Raising
water contents will certainly reduce its dissolving capacity, which further results in the
2 w
generation of aggregated nanoparticles in THF/H O mixture with a high f value. On the
other hand, intermolecular distance containing gold-gold distances will be altered and
aurophilic interactions will form [48]. The above factors will ultimately lead to the
enhancement of emission intensity and the appearance of red-shifted yellow emission.
Distinctively, replacing the substituents from non-aromatic rings to phenyl or naphthyl
ring, the aggregation behaviors for complexes 3-5 are special but consistent. Complexes
3-5 all began to emit when the f values were increased to 70% with new peaks at 419
w

ACCEPTED MANUSCRIPT
3
3
3
3
3
3
3
3
3
3
21
22
23
24
25
26
27
28
29
30
nm (3), 627 nm (4), and 512 nm (5), respectively. Meanwhile, their respective emission
intensity reached the maximum, while their emission weakened gradually when the f
w
value was increased continuously to 80% and even 90%. Herein, we have to address a
question: what’s the reason for the above subsequent quenching phenomenon. We
tentatively presume that further aggregations not only shortened the gold-gold distances,
but also tightened the intermolecular interactions between aromatic rings especially the
π-π interactions for complexes 4 and 5, which adversely lead to the quenching of the
initial luminescence. Actually, as collected in Table 2, the red-shifted absorptions after
aggregation might provide a support for our above presumption.
Insert Figure 7
3
3
3
3
3
3
3
3
3
3
31
32
33
34
35
36
37
38
39
40
4. Conclusion
In summary, five novel gold(I) complexes with various isocyanide ligands were
designed and synthesized. The elaborate modification of the terminal ligands has been
proved to effectively tune their photophysical properties. Alkyl modified complexes 1-3
exhibited tricolor or bicolor switching mechanochromic behaviors involved in a
reversible conversion between crystalline state and amorphous phase. Based on the
crystal analysis, the loosing packings formed through multiple intermolecular C–H···F
interactions might be the reason for the above mechanochromism. Conversely, the aryl
bridged complexes 4 and 5 are not mechano-responsive due to the tight and strong
intermolecular π-π packings. In addition, the structural difference of the terminal ligands

ACCEPTED MANUSCRIPT
3
3
3
3
3
3
3
3
3
41
42
43
44
45
46
47
48
49
gives rise to distinctive AIE characteristics for complexes 1-5. The X-ray single-crystal
analysis of complex 2 also indicates that the equatorial (e-) and axial (a-) conformers
could stably coexist and could realize a lower-energy intermolecular charge transfer,
which is quite rare in the similar gold systems and could provide new information for
related molecule designing. The above prominent mechanochromic properties may
establish the foundation for their applications in mechanical sensors, and chemical
detectors. All the complexes present typical AIE characteristics and these AIE-gens are
hoped to be used in the field of biomedical imaging.
Acknowledgements
3
3
50
51
The authors acknowledge financial support from National Natural Science
Foundation of China (21472059, 21772054), and the 111 Project (B17019).
3
52
Supporting Information Available
3
3
3
53
54
55
Crystallographic data for the structures in this paper have been deposited with the
Cambridge Crystallographic Data Centre as supplemental publication CCDC 1564070
(1), 1564074 (2), 1564075 (3), 1564076 (4), 1564091(5).
3
56
References
3
3
3
57
58
59
[1] Wang J, Jin B, Wang N, Peng T, Li X, Luo Y, et al. Organoboron-based
photochromic copolymers for erasable writing and patterning. Macromolecules
2017;50:4629-38.

ACCEPTED MANUSCRIPT
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
[2] Chorab MW, Tremblay MH, Skene WG. Hydrogen-bond and supramolecular-contact
mediated fluorescence enhancement of electrochromic azomethines. Chem Eur J
2016;22:11382-93.
[3] Sasaki S, Konishi G. Thermo-responsive fluorescence of AIE-active
poly(N-isopropylacrylamides) labeled with highly twisted bis(N,N-dialkylamino)arenes.
RSC Adv 2017;7:17403-16.
[4] Wen P, Gao Z, Zhang R, Li A, Zhang F, Li J, et al. A–π–D–π–A carbazole derivatives
with remarkable solvatochromism and mechanoresponsive luminescence turn-on. J Mater
Chem C 2017;5;6136-43.
[5] Deák A, Jobbágy C, Marsi G, Molnár M, Szakács Z, Baranyai P. Anion-, solvent-,
temperature-, and mechano-responsive photoluminescence in gold(I) diphosphine-based
dimers. Chem Eur J 2015;21:11495-508.
[6] Seki T, Tokodai N, Omagari S, Nakanishi T, Hasegawa Y, Iwasa T, et al.
Luminescent mechanochromic 9-anthryl gold(I) isocyanide complex with an emission
maximum at 900 nm after mechanical stimulation. J Am Chem Soc 2017;139:6514-17.
[7] Li Y, Ma Z, Li A, Xu W, Wang Y, Jiang H, et al. A single crystal with multiple
functions of optical waveguide, aggregation-induced emission, and mechanochromism.
ACS Appl Mater Interfaces 2017;9:8910-8.
[8] Gundu S, Kim M, Mergu N, Son YA. AIE-active and reversible mechanochromic
tetraphenylethene-tetradiphenylacrylonitrile hybrid luminogens with re-writable optical
data storage application. Dyes Pigments 2017;146:7-13.

ACCEPTED MANUSCRIPT
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
4
4
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
00
01
[9] Krishna GR, Devarapalli R, Lal G, Reddy CM. Mechanically flexible organic crystals
achieved by introducing weak interactions in structure: supramolecular shape synthons. J
Am Chem Soc 2016;138:13561-7.
[10] Toma O, Allain M, Meinardi F, Forni A, Botta C, Mercier N. Bismuth-based
coordination polymers with efficient aggregation-induced phosphorescence and
reversible mechanochromic luminescence. Angew Chem Int Ed 2016;55:7998-8002.
[11] Löwe C, Weder C. Oligo(p-phenylene vinylene) excimers as molecular probes:
deformation-induced color changes in photoluminescent polymer blends. Adv Mater
2002;14:1625-9.
[12] Ito H, Muromoto M, Kurenuma S, Ishizaka S, Kitamura N, Sato H, et al. Mechanical
stimulation and solid seeding trigger single-crystal-to-single-crystal molecular domino
transformations. Nat Commun 2013;4:2009-13.
[13] Zhang X, Wang JY, Ni J, Zhang LY, Chen ZN. Vapochromic and mechanochromic
phosphorescence
4-trifluoromethylphenylacetylide. Inorg Chem 2012;51:5569-79.
[14] Ni J, Zhang X, Qiu N, Wu YH, Zhang LY, Chen ZN, et al. Mechanochromic
luminescence switch of platinum(II) complexes with
5-trimethylsilylethynyl-2,2′-bipyridine. Inorg Chem 2011;50:9090-6.
materials
based
on
a
platinum(II)
complex
with
[15] Ni J, Wu YH, Zhang X, Li B, Zhang LY, Chen ZN. Luminescence vapochromism of
a platinum(II) complex for detection of low molecular weight halohydrocarbon. Inorg
Chem 2009;48:10202-10.

ACCEPTED MANUSCRIPT
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
[16] Yang L, Li X, Qin C, Shao KZ, Su ZM. A fluorescent sensor for highly selective
sensing of nitro explosives and Hg(II) ions based on a 3D porous layer metal–organic
framework. CrystEngComm 2016;18:4765-71.
[17] Cao HT, Ding L, Shan GG, Sun HZ, Wu Y, Su ZM. A sulfur-free iridium(III)
complex for highly selective and multi-signaling mercury(II)-chemosensors. Dalton
Trans 2015;44:19997-20003.
[18] Hou XG, Wu Y, Cao HT, Sun HZ, Shan GG, Su ZM, et al. A cationic iridium(III)
complex with aggregation-induced emission (AIE) properties for highly selective
detection of explosives. Chem Commun 2014;50:6031-4.
[19] Perruchas S, Le Goff XF, Maron S, Maurin I, Guillen F, Garcia A, et al.
Mechanochromic and thermochromic luminescence of a copper iodide cluster. J Am
Chem Soc 2010;132:10967-9.
[20] Wen T, Zhang D, Liu J, Zhang H, Zhang J. Facile synthesis of bimetal Au–Ag
nanoparticles in a Cu(I) boron imidazolate framework with mechanochromic properties.
Chem Commun 2015;51:1353-5.
[21] Deshmukh MS, Yadav A, Pant R, Boomishankar R. Thermochromic and
mechanochromic luminescence umpolung in isostructural metal–organic frameworks
6 6
based on Cu I clusters. Inorg Chem 2015;54:1337-45.
[22] Ito H, Saito T, Oshima N, Kitamura N, Ishizaka S, Hinatsu Y, et al. Reversible
mechanochromic luminescence of [(C F Au) (µ-1,4-diisocyanobenzene)]. J Am Chem
6
5
2
Soc 2008;130:10044-5.

ACCEPTED MANUSCRIPT
4
4
4
4
4
4
23
24
25
26
27
28
[23](a) Seki T, Ozaki T, Okura T, Asakura K, Sakon A, Uekusa H, et al. Interconvertible
multiple photoluminescence color of a gold(I) isocyanide complex in the solid state:
solvent-induced blue-shifted and mechano-responsive red-shifted photoluminescence.
Chem Sci 2015;6:2187-95. (b) Seki T, Takamatsu Y, Ito H. A screening approach for the
discovery of mechanochromic gold(I) isocyanide complexes with crystal-to-crystal phase
transitions. J Am Chem Soc 2016;138:6252-60.
4
4
4
4
4
4
4
4
4
4
4
4
4
29
30
31
32
33
34
35
36
37
38
39
40
41
[24](a) Chen Z, Zhang J, Song M, Yin J, Yu GA, Liu SH. A novel fluorene-based
aggregation-induced emission (AIE)-active gold(I) complex with crystallization-induced
emission enhancement (CIEE) and reversible mechanochromism characteristics. Chem
Commun 2015;51:326-9. (b) Chen Z, Liu G, Pu S, Liu SH. Bipyridine-based
aggregation-induced phosphorescent emission (AIPE)-active gold(I) complex with
reversible phosphorescent mechanochromism and self-assembly characteristics. Dyes
Pigments 2018;152:54-9. (c) Chen Z, Liu G, Pu S, Liu SH. Carbazole-based
aggregation-induced emission (AIE)-active gold(I) complex: Persistent room-temperature
phosphorescence, reversible mechanochromism and vapochromism characteristics. Dyes
Pigments 2017;143:409-15.
[25] Liang J, Chen Z, Yin J, Yu GA, Liu SH. Aggregation-induced emission (AIE)
behavior and thermochromic luminescence properties of a new gold(I) complex. Chem
Commun 2013;49:3567-9.

ACCEPTED MANUSCRIPT
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
[26] Susana I, Macarena P, Eduardo P. Cation-driven self-assembly of a gold(I)-based
metallo-tweezer. Angew Chem Int Ed 2017;56:9786-90.
[27] Yang W, Liu C, Lu S, Du J, Gao Q, Zhang R, et al. AIE-active smart cyanostyrene
luminogens: polymorphism-dependent multicolor mechanochromism. J Mater Chem C
2018;6:290-8.
[28] Luo J, Xie Z, Lam JWY, Cheng L, Chen H, Qiu C, et al. Aggregation-induced
emission of 1-methyl-1,2,3,4,5-pentaphenylsilole. Chem Commun 2001;0:1740-1.
[29] Mei J, Leung NLC, Kwok RTK, Lam JWY, Tang BZ. Aggregation-induced
emission: together we shine, united we soar! Chem Rev 2015;115:11718-940.
[30] Dong YQ, Lam JWY, Tang BZ. Mechanochromic luminescence of
aggregation-induced emission luminogens. J Phys Chem Lett 2015;6:3429-36.
[31] Pinto A, Svahn N, Lima JC, Rodríguez L. Aggregation induced emission of gold(I)
complexes in water or water mixtures. Dalton Trans 2017;46:11125-39.
[32] Yu Y, Luo Z, Chevrier DM, Leong DT, Zhang P, Jiang D, et al. Identification of a
highly luminescent Au22(SG)18 nanocluster. J Am Chem Soc 2014;136:1246-9.
[33] Shi L, Zhu L, Guo J, Zhang L, Shi Y, Zhang Y, et al. Self-assembly of chiral gold
clusters into crystalline nanocubes of exceptional optical activity. Angew Chem
2017;129:15599-603.
[34] Sinha N, Stegemann L, Tan TTY, Doltsinis NL, Strassert CA, Hahn FE. Turn-on
fluorescence in tetra-NHC ligands by rigidification through metal complexation: an
alternative to aggregation-induced emission. Angew Chem Int Ed 2017;56:2785-9.

ACCEPTED MANUSCRIPT
4
4
4
4
4
4
4
4
4
4
4
63
64
65
66
67
68
69
70
71
72
73
[35] Aguilo E, Gavara R, Lima JC, Llorca J, Rodriguez L. From Au(I) organometallic
hydrogels to well-defined Au(0) nanoparticles. J Mater Chem C 2013;1:5538-47.
[36] Chow ALF, So MH, Lu W, Zhu N, Che CM. Synthesis, photophysical properties,
and molecular aggregation of gold(I) complexes containing carbon-donor ligand. Chem
Asian J 2011;6:544-53.
[37] Hong EYH, Wong HL, Yam VWW. Tunable self-assembly properties of
amphiphilic phosphole alkynylgold(I) complexes through variation of the extent of the
aromatic π-surface at the alkynyl moieties. Chem Commun 2014;50:13272-4.
[38] Gavara R, Pinto A, Donamaría R, Olmos ME, Luzuriaga JML, Rodríguez L.
Polarized supramolecular aggregates based on luminescent perhalogenated gold
derivatives. Inorg Chem 2017;59:11946-55.
4
4
4
4
4
4
4
4
4
74
75
76
77
78
79
80
81
82
[39](a) Dong YB, Chen Z, Yang L, Hu YX, Yin J, Liu SH, et al. Effect of alkyl chain
length on the luminescence on-off mechanochromic behavior of solid-state Gold(I)
isocyanide complexes. Dyes Pigments 2018;150:315-22. (b) Chen Z, Li Z, Hu F, Yin J,
Yu GA, Liu SH. Novel carbazole-based aggregation-induced emission-active gold(I)
complexes with various mechanofluorochromic behaviors. Dyes Pigments
2016;125:169-78. (c) Chen Z, Nie Y, Liu SH. Fluorene-based mononuclear gold(I)
complexes: the effect of alkyl chain, aggregation-induced emission (AIE) and
mechanochromism characteristics. RSC Adv 2016;6:73933-8. (d) Chen Z, Li Z, Yang L,
Liang J, Yin J, Yu GA, Liu SH. Novel diisocyano-based dinuclear gold(I) complexes

ACCEPTED MANUSCRIPT
4
4
83
84
with aggregation-induced emission and mechanochromism characteristics. Dyes
Pigments 2015;121:170-7.
4
4
4
85
86
87
[40] R. Usón, A. Laguna, J. Vicente, J. García, B. Bergareche, P. Brun. Neutral
isocyanide and carbene pentafluorophenyl complexes of gold(I) and gold(III). Inorg
Chim Acta 1978;28:237-43.
4
4
4
88
89
90
[41] R. Usón, A. Laguna, J. Vicente, J. Preparation and properties of stable salts
containing mono- or bis-(pentafluorophenyl)aurate(I) and mono-, tris-, or
tetrakis-(pentafluorophenyl)aurate(III) ions. J Chem Soc Chem Commun 1976;0:353-4.
4
4
91
92
[42] Usón R, Laguna A, Laguna M. (Tetrahydrothiophene)gold(I) or gold(III) complexes.
Inorg Synth 1989;26:85-91.
4
4
4
4
4
4
4
5
93
94
95
96
97
98
99
00
[43] White-Morris RL, Olmstead MM, Balch AL. Aurophilic interactions in cationic gold
complexes with two isocyanide ligands. polymorphic yellow and colorless forms of
I
[(cyclohexyl isocyanide)
2
Au ](PF
6
) with distinct luminescence. J Am Chem Soc
2003;125:1033-40.
[44](a) Galet A, Muñoz MC, Real JA. Coordination polymers undergoing spin crossover
and reversible ligand exchange in the solid. Chem Commun 2006;0:4321-3; (b) Brandys
MC, Puddephatt RJ. Polymers and rings in gold(I) diphosphine complexes: linking gold
rings through aurophilic interactions. Chem Commun 2001;0:1280-1.

ACCEPTED MANUSCRIPT
5
5
5
5
5
5
5
5
5
5
01
02
03
04
05
06
07
08
09
10
[45] Lane TM, Grubisha DS, Hu C, Bennett DW. The structure of
trans-1,4-diisocyanocyclohexane in solution, in the solid state, and as a ligand bridging
bulky tungsten(II) complexes. J Mol Struct 1994;328:133-44.
[46] Yang Z, Chi Z, Yu T, Zhang X, Chen M, Xu B, et al. Triphenylethylene carbazole
derivatives as a new class of AIE materials with strong blue light emission and high glass
transition temperature. J Mater Chem 2009;19:5541-6.
[47] Leung CWT, Hong Y, Chen S, Zhao E, Lam JWY, Tang BZ. A photostable AIE
luminogen for specific mitochondrial imaging and tracking. J Am Chem Soc
2013;135:62-5.

ACCEPTED MANUSCRIPT
5
11
Table of Contents
5
5
5
5
12
13
14
15
1. Figure 1. Molecule structure of complexes 1-5.
3
2. Scheme 1. Reagents and conditions: i) HCOOH, reflux; ii) Triphosgene, Et N,
2 2 2 3 6 5 2 2
CH Cl ; iii) C10H21Br, K CO , DMF; iv) Au(C F )(tht), CH Cl , tht =
tetrahydrothiophene.
5
5
5
5
5
5
5
5
16
17
18
19
20
21
22
23
3. Table 1 Optical properties of complexes 1-5 in solid states.
4. Figure 2. (a) PL spectra ( ex = 365 nm) and (b) XRD patterns of complex
λ
1
in
different solid states. (c) Photographs of complex
under the 365 nm UV lamp.
1 in different situations taken
5. Figure 3. Photographs of complexes 2(a) and 3(b) in different situations taken
under the 365 nm UV lamp.
6. Figure 4. (a) The single crystal structure of complex 2. (b) Intermolecular interactions
and (c) crystal packing diagram of complex 2.
5
5
24
25
7. Figure 5. (a) The single crystal structure of complex 4. (b) Intermolecular interactions
and (c) crystal packing diagram of complex 4.
5
5
5
26
27
28
8. Figure 6. The molecular orbitals and corresponding energies of monomer (e- and
a-conformer) and dimer of complex 2. The geometry optimizations are based on the
crystal structures.
5
29
9. Table 2 Optical properties of complexes 1-5 in solution and aggregates.

ACCEPTED MANUSCRIPT
5
5
5
5
5
5
30
31
32
33
34
35
10. Figure 7. PL spectra (a) of the dilute solutions of complex
5
(20 µM,
). (b) Plot of relative
of the THF/water mixture, where
= emission intensity in THF solution. (c) Photos taken
under 365 nm UV light of complex in THF-water mixtures.
λex = 325
nm) in THF/H
emission peak intensity (
= emission intensity and 0
2
O mixtures with various water fractions (
f
w
I
/I
0
) at 512 nm versus
f
w
I
I
5
5
5
36
37
Figure 1. Molecule structure of complexes 1-5.