Journal of the American Chemical Society
Page 8 of 13
1
spectrum of 3 a single Voigt was employed to model the white-line
volatiles removed in vacuo to afford 6 (11.677 g, 72%). H NMR (500.3
t
1
2
3
4
5
6
7
8
9
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
6
feature. The area under the Voigt functions (defined as the intensity)
MHz, C
6
D
6
): 3.08-3.04 (2H, m, (CH
2
N Bu)), 2.82-2.75 (2H, m,
1
/2
t
13
was calculated with the formula ph×fwhm×1/4×([π/ln(2)] +π), where
(CH
MHz, C
Hz, CH
MHz, C D ): 157.54 (s). IR: [cm ] = 1396 (w), 1376 (m), 1363 (m),
2
N Bu)), 1.24 (18H, d, J = 2.1 Hz, NC(CH ) ). C NMR (125.8
3 3
2
2
ph = peak height (normalized intensity), fwhm = full-width at half-
6
D
6
t
): 53.55 (d, JCP = 10.9 Hz, NC(CH
3
)), 45.28 (d, JCP = 10.5
1
/2
3
). 31P NMR (202.5
maximum height (eV), and the value 1/4×([π/ln(2)] +π) ≈ 1.318 is a
constant associated with the Voigt function. The fits are shown in Fig.
S45 and summarized in Table S17. Relative parameter error estimates
are calculated from the covariance matrix assuming normally
2
N Bu), 28.81 (d, JCP = 11.9 Hz, NC(CH
3 3
)
-1
6
6
1268 (w), 1256 (w), 1244 (w), 1221 (s), 1208 (s), 1128 (m), 1120 (m),
1088 (w), 1040 (m), 1026 (w), 982 (m), 863 (w), 802 (w), 676 (w), 665
(w). Elemental analysis found(calculated): C, 50.98(50.74), H,
9.38(9.37), N, 11.97(11.83).
distributed variances in the data. Absolute error in n
0%.
Theoretical Calculations. All the calculations were carried out with
f
is about 0.04 or
1
t
[P(1,2-bis- Bu-diamidoethane)(NEt )], 7. Inside a glovebox, 6
2
5
5
the PBE0 hybrid functional as implemented in the Gaussian 09
(11.59 g, 49 mmol) was added to a 500 mL Schlenk round bottom flask
equipped with a Teflon stir bar and dissolved in 200 mL of diethyl
ether. The flask was transferred to the Schlenk line and cooled to 0 °C.
Diethylamine (20 mL, 196 mmol) was added dropwise to the solution
over 5 min. A thick, white precipitate quickly formed. The reaction
mixture was stirred for 20 h at 25 °C and then transferred to the
glovebox where it was filtered through a medium porosity frit packed
with Celite and washed with two times with 15 mL of diethyl ether to
yield a clear, colorless filtrate. Volatiles were removed in vacuo to yield
a clear, colorless, viscous liquid. The liquid was distilled at 55 – 58 °C
at ~170 mtorr to afford the title compound as a clear, colorless liquid
5
6
57
software package revision C.01. ECP28MWB small core quasi-
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
5
8
relativistic pseudopotential and ECP28MWB_ANO basis set were
used to describe Tb, and the remaining atoms were described with the
all-electron Pople basis set 6-311G(d). The geometries of compounds
59
+
3
2
(excluding the K(Et O) counter ion fragment) and 4 were optimized
in gas phase without any constraints. Harmonic frequency calculations
were performed to confirm that the optimized structures were
stationary points on the potential energy surface. The computed
structural metrics are in good agreement with the XRD data, with Tb−N
and N−P bond distances, as well as Tb−N−P valence angles within
3.9%, 0.4%, and 3.3% of the experimental ones, respectively, providing
confidence to the theoretical model (Table S13). In all calculations,
1
(12.52 g, 93%). H NMR (500 MHz, C D ): 3.19-3.16 (2H, m,
CH N Bu), 3.06 (4H, p, J = 7.1 Hz, NCH CH ), 2.87-2.83 (2H, m,
CH N Bu), 1.29 (18H, s, NC(CH ) ), 1.07 (6H, t, J = 7.1 Hz,
2 3 3
2 3 6 6
NCH CH ). C NMR (MHz, C D ): 52.36 (d, J = 17.9 Hz), 45.36 (d,
6
6
t
2
2
3
2
t
spin contamination was found to be less than 5.2% with ⟨S ⟩ values
1
3
being close to the corresponding values of the considered spin states,
i.e. septet for 3 (C
2
point group symmetry) and octet for 4 (S
4
point
J = 8.2 Hz), 40.26 (d, J = 20.2 Hz), 29.50 (d, J = 10.2 Hz), 14.94 (d, J
31
1
-1
group symmetry). Wavefunctions of the studied species were found to
be stable indicating that the calculations converged to the ground
electronic state. Time-dependent DFT calculations (TD-DFT) of up to
= 3.1 Hz). P{ H} NMR (MHz, C D ): 100.44 (s). IR: [cm ] = 1458
6
6
(w), 1387 (m), 1369 (w), 1358 (m), 1340 (w), 1288 (w), 1261 (m), 1242
(m), 1219 (m), 1195 (m), 1133 (m), 1094 (w), 1052 (w), 1031 (w), 1014
(m), 965 (m), 906 (m), 865 (m), 787 (m), 668 (m), 632 (w). Elemental
analysis found(calculated): C, 61.26(61.50), H, 11.50(11.80), N,
14.64(15.37).
2
00 excited states were carried out to simulate the experimental UV-
Vis spectrum of both complexes. The computed UV-Vis spectra were
plotted broadening the calculated excitation lines with Gaussian-type
peaks using 0.05 eV half-width at half height. Natural transition orbitals
t
2
[HN=P(1,2-bis- Bu-diamidoethane)(NEt )], 8. The title compound
6
0
(
NTOs), which most of the time can yield a single electron-hole
was prepared through a one flask, two-step reaction sequence. Inside a
glove box, 7 (4.058 g, 15 mmol) was dissolved in 25 mL of toluene
inside a 100 mL Schlenk pear flask equipped with a Teflon stir bar.
Trimethylsilylazide (32 mmol) was added to the flask and the flask was
transferred to the Schlenk line. The reaction mixture was refluxed for
3 d. Volatiles were removed in vacuo to yield a yellow residue. Dry,
degassed methanol (24 mL, 596 mmol) and 2 drops of 96% H SO were
representations of the electronic excitations, were employed to interpret
the calculated excitation spectra. To gain more insight into electronic
structure of these complexes, chemical bonding analyses were
6
1, 62
performed using Natural Bond Orbital
(NBO6) method. The
6
3
GaussView 6 was used for molecular orbitals visualization of the
6
4
NBO results. Chemissian 4.60 was used to plot molecular orbital
energy level diagrams.
Syntheses. A scheme providing an overview for all syntheses is
provided in Figure S1.
2
4
added. The yellow solution was stirred at 25 °C for 2 d. Volatiles were
removed in vacuo to yield a viscous, turbid, yellow liquid. The liquid
was transferred to a 50 mL Schlenk round bottom flask and distilled at
75 – 78 °C at 60 mtorr to yield the product as a viscous, clear, colorless
N,N’-di-tert-butylethylenediamine, 5. Synthesis of 5 was modified
6
5
1
from a previous report. In air, 1,2-dibromoethane (86 mL, 1 mol) and
50 mL of water were added to a 2 L round bottom flask equipped with
liquid (1.94 g, 45%). H NMR (500 MHz, C D ): 3.21-3.15 (4H, dq, J
6
6
3
t
2
= 10.2, 7.1 Hz, NCH CH ), 2.76-2.65 (4H, m, (CH N Bu) ), 1.29 (18H,
2
3
2
a Teflon stir bar. The reaction mixture was chilled to 0 °C, and tert-
butylamine (526 mL, 5 mol) was added dropwise to the solution. The
reaction mixture was kept in an ice bath for 1 h and then stirred at 25
3 3 2 2 3
s, (NC(CH ) ) ), 1.09 (6H, t, J = 7.1 Hz, NCH CH ), 0.37 (1H, br s,
P=N-H). 13C{
1
H} NMR (500 MHz, C D ): 52.6 (d, J = 5.4 Hz,
6
6
t
NC(CH ) ), 40.7 (d, J = 10.8 Hz, CH N
3
3
2
Bu), 40.4 (d, J = 4.6 Hz,
°
C for 4 d. Solid NaOH was added in 25 g portions until it no longer
NCH CH ), 28.6 (d, J = 3.1 Hz, NC(CH ) ), 14.1 (d, J = 2.7 Hz,
2
3
3 3
dissolved (no change over 3 h). The biphasic mixture was then decanted
and stirred over an additional 25 g of ground NaOH for 30 h. The top
layer was then obtained via separatory funnel and the liquid was filtered
into a 250 mL Schlenk round bottom flask. Pre-sliced pieces of Na
31
1
-1
NCH
2
CH
3
). P{ H} NMR (500 MHz, C
6
D
6
): 30.7 (s). IR: [cm ] =
3
1
389 (m), 1479 (m), 1465 (m), 1391 (s), 1378 (s), 1361 (s), 1268 (s),
248 (s), 1225 (s), 1208 (s), 1192 (s), 1150 (s), 1108 (s), 1091 (w), 1052
(s), 1035 (s), 1019 (w), 979 (s), 944 (s), 869 (s), 800 (m), 789 (w), 693
metal were added (~ 4 g) and the mixture was distilled at 66 – 69 °C at
(
m), 645 (m), 617 (w). Elemental analysis of the air-sensitive liquid
1
~30 torr to yield a clear, colorless liquid (97.13 g, 56%). H NMR (400
t
was not performed. The =NTMS intermediate, [TMSN=P(1,2-bis- Bu-
t
t
6 6 2 2
MHz, C D ): 2.57 (4H, s, (CH N Bu)), 1.04 (18H, s, (CH N Bu)), 0.77
2
diamidoethane)(NEt )], can be isolated, if desired, prior to the addition
(
2H, HN).
of methanol and sulfuric acid through removal of volatiles in vacuo and
t
[
(CH
2
6
N Bu)
2
PCl], 6. Synthesis of 6 was modified from a previous
1
crystallization from hexanes at -35 °C. H NMR (500 MHz, C
6
t
D
6
): 2.99
N Bu), 2.64
), 1.04 (6H, t, J = 7.2 Hz),
). C{ H} NMR (500 MHz, C ): 52.4 (d, J
N Bu), 40.4 (d, J = 12.6
), 14.2 (d, J = 3.0 Hz,
6
report. PCl
3
(6 mL, 68.6 mmol) was added to a 500 mL Schlenk round
(
4H, dq, J = 11.1, 7.2 Hz, NCH
2
CH
3 2
), 2.76 (2H, m, CH
bottom flask containing 350 mL diethyl ether and a Teflon stir bar. The
reaction mixture was cooled to -20 °C and triethylamine (50 mL, 360
mmol) was added to the reaction mixture and, subsequently, 5 (15 mL,
t
(2H, m, CH
.44 (9H, s, =N-Si(CH
4.7 Hz, NC(CH ), 40.9 (d, J = 6.4 Hz, CH
Hz, NCH CH ), 28.04 (d, J = 7.7, NC(CH
NCH CH ), 4.63 (d, J = 2.5 Hz, =N-Si(CH
MHz, C ): -0.25 (s). Elemental analysis found(calculated): C,
6.81(56.62), H, 11.34(11.46), N, 15.55(15.54).
2
N Bu), 1.25 (18H, s, NC(CH )
3 3
13
1
0
=
3
)
3
6 6
D
t
3
)
3
2
6
9.6 mmol) was added dropwise over 15 min. A thick, white precipitate
2
3
3 3
)
quickly formed. The reaction mixture was stirred for 6 h at 25 °C and
then transferred to the glovebox where it was filtered through a medium
porosity frit packed with Celite and washed twice with 30 mL diethyl
ether to yield a clear, colorless filtrate. The solution was concentrated
in vacuo and placed inside a -35 °C freezer overnight. Colorless,
needle-like crystals were isolated by decantation and the remaining
31
1
2
3
3 3
) ). P{ H} NMR (500
6
D
6
5
t
[
2 2 2
(CH N Bu) (Et N)P=NK], 2. Inside a glovebox, 8 (1.273 g, 4.413
mmol) was added to a 20 mL scintillation vial equipped with a Teflon
stir bar and dissolved in 4 mL of hexanes. Potassium benzyl (0.576 g,
8
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