S
1
Supporting Information for
Fusing
Triphenylphosphine
with
Tetra
phenylborate: Introducing
the
9
-
Phosphatriptycene
-
10
-
Phenylb
orate
(PTB)
Anion
Marcus W.
Drover,
†
Koichi Nagata,
†
and Jonas C. Peters
*
†
These
authors contributed equally
*
E
-
mail:
jpeters@caltech.edu
*
Division of
Chemistry and Chemical Engineering, California Institute of Technolog
y,
Pasadena, California, 91125
, United States
1. General Considerations
S2
2. Synthetic Procedures
S3
3. Electrochemistry
S
30
4. Crystallography
D
iscussion and
T
ables
S
31
5.
Density
F
unctional Theory
S
3
6
6
. References
S
3
7
Electronic
Supplementary
Material
(ESI)
for
ChemComm.
This
journal
is
©
The
Royal
Society
of
Chemistry
2018
S
2
General Considerations
:
All experiments were carried out employing standard Schlenk techniques under an
atmosphere of dry nitrogen or argon e
mploying degassed, dried solvents in a solvent
purification system sup
plied by SG Water, LLC.
Non
-
halogenated solvents were tested
with a standard purple solution of sodium benzophenone ketyl in
THF
in order to confirm
effective moisture r
e
moval.
P(
o
-
BrC
6
H
4
)
3
1
,
5
-
azonia
spiro[4.4]nonane bromide
(
[ASN]Br
)
2
,
and W(CO)
5
THF
w
ere
prepared according to a literature procedure
. All
other reagents were purchased from commerc
ial vendors and used without further
purification unless otherwise stated.
Physical methods
:
Fourier transform infrared ATR (FT
-
IR ATR) spectra were collected on a
Bruker Alpha
Platinum ATR spectrometer using OPUS software
. NMR data were collected on a V
arian
300 or
400 MHz instrument with chemical shifts reported in ppm relative to
deuterated
solvent
, using residual solvent re
sonances as internal standards.
31
P chemical shifts are
reported in ppm relative to 85% aqueous H
3
PO
4
. UV
-
Visible spectroscopy mea
surements
were collected with a Cary 50 UV
-
Vis spectrophotometer using a 1 cm two
-
window
quartz cell.
•
57
Fe Mössbauer
:
Mössbauer spectra were recorded on a spectrometer from SEE Co. (Edina, MN)
operating in the constant acceleration mode in transmission ge
ometry. The sample
was kept in an SVT
-
400 cryostat for
m Janis (Wilmington, MA), using
liquid N
2
as a cryogen for 80 K measurements. The quoted isomer shifts are relative to the
centroid of the spectrum of a metallic fo
il of
α
-
Fe at room temperature.
Soluti
on
samples were transferred to a sample cup and chilled to 77 K inside of the
glovebox, and quickly removed from the glovebox and immersed in liquid N
2
until mounted in the cryostat. Da
ta analysis was performed using
WMOSS
version 4
(www.wmoss.org) and qua
drupole doublets wer
e fit to Lorentzian
lineshapes.
3
S
3
Synthetic Procedures:
Tetrakis
(tetrahydrofuran)
lithium
phosphatriptycene
-
10
-
phenyl
borate ([
3
][Li(THF)
4
]): A
solution
of
n
BuLi (1.6 M, 1.1 mL, 1.7 mmol) in hexane was added dropwise to a solution
of
tris
(2
-
bromophenyl)phosphine
1
(
288
mg, 578.0
μ
mol) in Et
2
O (80 mL) and THF (24
mL) at
–
78
°
C. Following addition, the resulting mixture
was stirred for an additional 2 h
at
-
78
°
C and a solution of
PhBCl
2
(70.0
μ
L, 578
μ
mol) in Et
2
O (20 mL) was added drop
wise to the mixture at
–
78
°
C. Subsequently, the mixture was allowed to warm to 0
°
C and
then stirred for an additional 24 h. Next, all
volatiles were removed
in
-
vacuo
and the
residue was dissolved in C
6
H
6
and filtered though a pad of Celite
®
. The resulting pale
yellow solid was dissolved in THF and again filtered through a pad of Celite
®
.
Concentration of
the filtrate and cooling at
–
35
ºC afforded [
3
][Li(THF)
4
] as a pale
yellow solid
(
238 mg
, 64%).
1
H NMR (CD
3
CN, 400 MHz, 298 K)
:
δ
=
8.
10 (br, 2H;
o
-
Ph), 7.65 (d,
3
J
H,H
= 7.2 Hz,
3H), 7.47 (br,
2
H), 7.45 (t,
3
J
H,H
= 7.2 Hz, 3H;
m
-
Ph), 7.26 (t,
3
J
H,H
= 7.2 Hz, 1H;
p
-
Ph),
6.91 (t,
3
J
H,H
= 7.2 Hz, 3H), 6.83 (t,
3
J
H,H
= 7.2 Hz, 3H
),
3.71 (m, 16H, THF),
1.84 (m,
16H, THF
).
7
Li
{
1
H}
NMR
(CD
3
CN, 156 MHz, 298 K):
δ
=
–
1.2.
31
P{
1
H} NMR (THF
-
d
8
, 162 MHz, 298 K)
:
δ
=
–
43.7 (d,
3
J
P,
B
= 3.8 Hz).
11
B{
1
H} NMR (CD
3
CN, 128 MHz, 298 K)
:
δ
=
–
8.75 (d,
3
J
P,
B
= 3.8 Hz).
13
C NMR (THF
-
d
8
, 100 MHz, 298 K)
:
δ
= 147.3, 137.4, 132.1, 131.6, 131.5, 126.5
,
124.9, 122.7, 120.8, 120.7, 58.6, 46.0
.
HR ESI(
-
)
-
MS:
Calcd
.
347.1838
for C
24
H
17
BP
[
3
]
-
.
Found
.
347.1814
P
Br
Br
Br
n
BuLi
(3.0
equiv.),
-78
o
C,
2
h
Ph
B
Cl
2
,
-78
o
C,
1.5
h
5:1
Et
2
O/THF
P
B
Ph
Li(THF)
4
-78
o
C
to
0
o
C,
12
h
0
o
C
to
r.t.,
12
h
[
3
][Li(THF)
4
]
(64%)
S
4
Figure S1.
[
3
][Li(THF)
4
],
1
H NMR, CD
3
CN, 400 MHz, 298 K
Figure S2.
[
3
][Li(THF)
4
],
7
Li{
1
H} NMR, CD
3
CN, 156 MHz, 298 K
P
B
Ph
Li(THF)
4
P
B
Ph
Li(THF)
4
S
5
Figure S
3
.
[
3
][Li(TH
F)
4
],
31
P{
1
H} NMR, THF
-
d
8
, 162 MHz, 298 K
Figure S
4
.
[
3
][Li(THF)
4
],
11
B{
1
H} NMR, CD
3
CN, 128 MHz, 298 K
P
B
Ph
Li(THF)
4
P
B
Ph
Li(THF)
4
S
6
Figure S5.
[
3
][Li(THF)
4
],
13
C{
1
H} NMR, THF
-
d
8
, 100 MHz, 298 K
P
B
Ph
Li(THF)
4
S
7
Route A
:
Tetra
ethylammonium
9
-
phosphatriptycene
-
10
-
phenyl
b
orate ([
3
][
NEt
4
]):
To a
stirring MeOH (1 mL)
solution of [
3
][Li(THF)
4
] (13
mg, 20.4
μ
mol
) was added
[NEt
4
]Br
(4.3 mg, 20.4
μ
mol) in MeOH (1 mL) at room temperature. Within minutes, a white
precipitate formed. Af
ter 30 min, the resulting white solid
was col
lected by filtration and
washed with MeOH (4
×
1 mL). The solids were dried
in
-
vacuo
providing
[
3
][
NEt
4
] (12
mg, 97%).
The filtrate wa
s concentrated and stored at
–
35
ºC to afford
[
3
][
NEt
4
]
as
colorless crystals.
Route B
:
Tetra
ethylammonium
9
-
phosphatrip
tycene
-
10
-
phenyl
borate ([
3
][
NEt
4
]):
An
oven
-
dried 1000
mL three
-
neck flask was fitted with a
flow control two
-
way
-
glass
adapter, rubber septum
, and a 100
mL liquid addition funnel capped with a rubber
septum. Under an N
2
atmosphere, the flask was charged w
ith
tris
(2
-
bromophenyl)phosphine
1
(
2.044 g
,
4.096
mmol), a
mixture of Et
2
O (
60
0 mL)
:
THF (
2
00
mL), and a magnetic stir bar. The addition funnel was charged with 1.
7
M
t
BuLi in
pentane (1.7
M,
13.3
mL,
22.5
mmol) and t
he
three
-
neck flask was cooled in a
acetone/dry ice
slush bath (~
–
78
º
C) with vigorous stirring for ~ 10 min.
Addition of
t
BuLi was commenced drop
wise over
2
5
min
.
The addition funnel was washed with
Et
2
O (10 mL) and subsequently added over 3 min, causin
g a color change to dark green.
The reaction mixture was allowed to stir at
–
78 ºC for 2 h. The addition funnel was
subsequently charged with distilled PhBCl
2
(0.5 mL, 4.1 mmol) diluted in Et
2
O (52 mL).
This solution was added drop
wise over 1.
2
5 h
to the
vigorously stirred reaction
mixture, causing a color change to orange
.
After the mixture was stirred for an
additional 6 h, the mixture was allowed to warm gradually to 0 ºC overnight (
~
12 h). The
next morning, the mixture was allowed to warm gradually t
o room temperature.
After
12
P
B
Ph
Li(THF)
4
P
B
Ph
MeOH,
r.t.
[
3
][NEt
4
]
(97%)
[NEt
4
]Br
NEt
4
P
Br
Br
Br
t
BuLi
(5.5
equiv.),
-78
o
C,
2
h
Ph
B
Cl
2
,
-78
o
C,
1
h
5:1
Et
2
O/THF
-78
o
C
to
0
o
C,
12
h
0
o
C
to
r.t.,
12
h
P
B
Ph
MeOH,
r.t.,
12
h
[
3
][NEt
4
]
(30%)
[NEt
4
]Br
NEt
4