L. Wang, J. Cheng, Y. Ma et al.
Polyhedron 197 (2021) 115054
1
v
5.02 (s, v1/2 = 248 Hz), 11.04 (s, v1/2 = 207 Hz), 3.43 (s,
1/2 = 203 Hz), 2.02 (s, v1/2 = 212 Hz), 1.05 (s, v1/2 = 260 Hz),
6.88 (s, v1/2 = 169 Hz), ꢀ18.92 (s, v1/2 = 169 Hz), ꢀ53.05 (s,
310 (1720), 340 (1500), 400 (2100), 700 (680), 850 (380), 1380
(500), 1600 (600). IR (KBr, cm ): m = 3153 (w), 3052 (m), 3005
(m), 2919 (m), 2849 (m), 1579 (s), 1529 (w), 1488 (s), 1441 (m),
1374 (s), 1337 (m), 1253 (m), 1214 (m), 1176 (m), 1154 (m),
1056 (m), 1027 (m), 989 (w), 928 (w), 852 (m), 783 (w), 747 (s),
700 (s), 639 (w), 581 (w), 522 (w), 504 (w), 462 (w). 57Fe Möss-
ꢀ1
ꢀ
v
1/2 = 302 Hz), ꢀ108.83 (s, v1/2 = 388 Hz). Anal. Calcd for C32
42
H -
4
FeN : C, 71.37; H, 7.86; N, 10.40. Found: C, 70.35; H, 7.78 N,
1
0.48%. Multiple attempts to collect satisfied elemental analysis
data failed due to probably the high air- and moisture-sensitivity
of the complex. Magnetic susceptibility (C , 293 K): eff = 3.5
Q
bauer spectrum (zero-field, 80 K): d = 0.38 mm/s, |DE | = 3.58-
mm/s.
6
D
6
l
ꢀ1
ꢀ1
(
1)
B
l . Absorption spectrum (THF): kmax, nm (e, M cm ) = 280
ꢀ1
(
8500), 440 (4600), 1050 (240), 1450 (190). IR (KBr, cm ):
m
1
= 3123 (w), 3095 (w), 3004 (w), 2949 (m), 2919 (m), 2859 (w),
685 (s), 1593 (m), 1490 (s), 1456 (s), 1405 (m), 1379 (m), 1315
4.4.6. Catalytic cyclotrimerization reactions of catalyzed by 1
A toluene (1 mL) solution of the corresponding alkyne with 1
(5 mol %) as the catalyst was heated at 80 °C for 20 h. Then the
solution was exposed to air and wet n-hexane (3 mL) was added.
The mixture was then subjected to vacuum to remove all of the
volatiles. The residue was subjected to fast silica gel column chro-
matography that gave cyclotrimerization products as colorless
solids.
(
m), 1253 (w), 1208 (w), 1038 (m), 967 (w), 932 (w), 851 (m),
8
03 (w), 739 (m), 688 (w), 666 (w), 582 (w). 57Fe Mössbauer spec-
trum (zero-field, 80 K): d = 0.28 mm/s, |
D
E
Q
| = 3.55 mm/s.
2
4
.4.4. Synthesis of [(IMesMe)
2
Fe(
g
3
-PhCCCH )] (4)
To a red solution of 1 (1.95 g, 3.50 mmol, 1.0 equiv.) in n-hexane
(
10 mL) was added PhC„CCH (406 mg, 3.50 mmol, 1.0 equiv.) at
3
For the reaction of EtC„CEt (84.3 mg, 1.03 mmol), n-hexane
room temperature. The color of the solution changed to reddish
brown immediately. After stirring for 20 min, the volatiles were
removed under vacuum to leave a reddish brown residue, which
was used as the eluent for separation, and the product C
6
Et
6
was
1
isolated in 52% yield. H NMR (400 MHz, CDCl
2.67 (q, J = 7.5 Hz, 12H), 1.22 (t, J = 7.5 Hz, 18H). C NMR
(101 MHz, CDCl , 298 K): d (ppm) 137.4, 21.7, 15.3. These NMR
data are in accordance with that reported in literature [30].
For the reaction of PhC„CCH (122.4 mg, 1.05 mmol), n-hex-
ane/EA (40:1) was used as the eluent for separation, and the pro-
duct 1,2,4-Me -3,5,6-Ph
was isolated in 74% yield. 1H NMR
(400 MHz, CDCl , 298 K): d (ppm) 7.46–7.32 (m, 4H), 7.26–7.22
(m, 2H), 7.14–7.07 (m, 4H), 7.05–6.96 (m, 5H), 2.04 (s, 6H), 1.72
3
, 298 K): d (ppm)
1
3
was washed with hexamethyldisiloxane (5 ꢁ 3 mL) and dried
3
2
under vacuum, which afforded [(IMesMe)
2
Fe(
g
-PhCCMe)] (4) as
a brown solid (1.96 g, 98%). 1H NMR (400 MHz, C
, 298 K): d
ppm) 64.00 (s, v1/2 = 226 Hz), 62.57 (s, v1/2 = 239 Hz), 36.67 (s,
6
D
6
3
(
v
1/2 = 243 Hz), 29.76 (s, v1/2 = 77.8 Hz), 27.42 (s, v1/2 = 69.8 Hz),
4.31 (s, v1/2 = 63.8 Hz), 23.96 (s, v1/2 = 63.8 Hz), 16.65 (s,
1/2 = 51.9 Hz), 10.58 (s, v1/2 = 109 Hz), ꢀ5.81 (s, v1/2 = 64.0 Hz),
10.91 (s, v1/2 = 38.0 Hz), ꢀ16.70 (s, v1/2 = 84.0 Hz), ꢀ46.67 (s,
167 Hz), ꢀ48.18 (s, 167 Hz), ꢀ96.28 (s,
1/2 = 363.1 Hz), ꢀ97.70 (s, v1/2 = 331 Hz). Anal. Calcd for C35
: C, 73.42; H, 7.04; N, 9.79. Found: C, 71.92; H, 7.14; N,
.02% Multiple attempts to collect satisfied elemental analysis data
failed due to probably the high air- and moisture-sensitivity of the
3
3 6
C
2
v
3
1
3
ꢀ
3
(s, 3H). C NMR (101 MHz, CDCl , 298 K): d (ppm) 142.5, 141.7,
v
v
1/2
=
v
1/2
=
141.7, 141.5, 140.7, 139.3, 134.0, 132.0, 131.3, 130.4, 129.5,
128.5, 127.4, 127.4, 126.5, 125.8, 125.7, 19.5, 18.4, 18.2. These
NMR data are in accordance with the literature [31].
40
H -
FeN
4
9
For the reaction of PhC„CPh (178.6 mg, 1.00 mmol), n-hexane/
EA (20:1) was used as the eluent for separation, and the product
1
complex. Magnetic susceptibility (C
Absorption spectrum (THF): kmax, nm (
6
D
6
, 293 K):
l
eff = 3.2(1)
l
B
.
C Ph
6 6
was isolated in 42% yield. H NMR (400 MHz, CDCl
3
,
ꢀ
1
ꢀ1
13
e, M cm ) = 280 (9100),
3
298 K): d (ppm) 6.84 (s, 30H). C NMR (101 MHz, CDCl , 298 K):
3
00 (7900), 360 (6400), 420 (4700), 700 (230), 1080 (150), 1400
d (ppm) 140.6, 140.3, 131.4, 126.5, 125.1. These NMR data are in
accordance with the literature [30].
ꢀ1
(
150). IR (KBr, cm ):
w), 2916 (m), 2890 (m), 2855 (w), 1754 (s), 1682 (m), 1607 (w),
583 (s), 1487 (s), 1478 (s), 1436 (m), 1386 (m), 1340 (m), 1320
m), 1246 (m), 1214 (m), 1167 (w), 1051 (m), 996 (w), 927 (w),
m
= 3125 (w), 3042 (w), 2999 (w), 2945
(
1
(
4.5. Computational details
8
5
8
49 (m), 751 (w), 696 (s), 667 (m), 582 (w), 539 (w), 525 (w),
15 (w), 463 (w), 430 (w). 57Fe Mössbauer spectrum (zero-field,
To have a better understanding on the electronic structures of 1
and 5, DFT [32,33] study was performed with the ORCA 4.1.0 pro-
gram [34] using the B3LYP methods [35,36]. The SVP [37,38] basis
set was used for the C, N, and H atoms, and the TZVP [39] basis set
was used for the other atoms. The RIJCOSX [40] approximation
with matching auxiliary basis sets was employed to accelerate
the calculations. The calculation utilizes the atom-pairwise disper-
sion correction with the Becke–Johnson damping scheme (D3BJ)
[41,42]. The atomic coordinates of 1 and 5 used for calculation
were obtained from X-ray diffraction studies, and only the posi-
tions of hydrogen atoms were optimized. Table S2 summarizes
the corresponding single point energies relative to the S = 0, 1
and 2 states. The selected UNO orbitals of 1 and 5 are listed in
Figs. 2 and 6.
0 K): d = 0.43 mm/s, |
D
Q
E | = 3.02 mm/s.
4
4.4.5. Synthesis of [(IMesMe)
2
Fe(
g
3 3
-C(Ph)C(CH )C(Ph)C(CH ))] (5)
To a red solution of 1 (278 mg, 0.50 mmol, 1.0 equiv.) in n-hex-
ane (20 mL) was added PhC„CMe (290 mg, 2.50 mmol, 5.0 equiv.)
at room temperature. The color of the solution changed to dark
green gradually with precipitation of a solid. After stirring for
2
4 h, the solid was collected by filtration, washed with n-hexane
(
3 ꢁ 4 mL) and Et O (3 ꢁ 4 mL). and then dried under vacuum to
2
give a brownish green solid. The solid was then dissolved in a min-
imal amount of THF and the solution was then filtrated. Green
crystals of 5 were obtained by standing the THF solution at room
temperature for days. Yield: 75 mg, 21%. 1H NMR (400 MHz,
6
C D
6
, 298 K): d (ppm) 42.51 (s, v1/2 = 41.6 Hz), 30.98 (s,
v1/2 = 40.4 Hz), 21.17 (s, v1/2 = 39.6 Hz), 19.54 (s, v1/2 = 65.2 Hz),
7
.50 (s, v1/2 = 35.4 Hz), 1.24 (s, v1/2 = 30.2 Hz), ꢀ0.35 (s,
CRediT authorship contribution statement
v
v
v
1/2
=
=
33.2 Hz), ꢀ7.08 (s,
192 Hz), ꢀ45.96 (s,
v
1/2
=
=
62.5 Hz), ꢀ42.26 (s,
73.8 Hz), ꢀ70.23 (s,
1/2
v
1/2
Lijun Wang: Investigation, Writing - original draft, Writing -
review & editing. Jun Cheng: Investigation, Validation, Writing -
original draft, Writing - review & editing. Yingjie Ma: Investiga-
tion. Qi Chen: Investigation. Xuebing Leng: Investigation. Liang
Deng: Conceptualization, Supervision, Writing - review & editing.
1/2 = 56.9 Hz), ꢀ186.91 (s, v1/2 = 274 Hz). Anal. Calcd for C44
48
H -
FeN
.07%. Magnetic susceptibility (C
Absorption spectrum (THF): kmax, nm (
4
: C, 76.73; H, 7.02; N, 8.13. Found: C, 76.10; H, 7.04; N,
8
6
D
6
, 293 K): eff = 3.2(1) l .
l
B
ꢀ
1
ꢀ1
e, M cm ) = 270 (2020),
8