A Modular Approach to Phosphorescent π-Extended Heteroacenes

Article abstract of DOI:10.1021/acs.inorgchem.9b02213

A modular route to previously inaccessible classes of ring-fused π-extended heteroacenes bearing the heavy inorganic element tellurium (Te) is presented. These new materials can be viewed as n-doped analogs of molecular graphene subunits that exhibit color tunable visible light phosphorescence in the solid state and in the presence of air. The general mechanism of phosphorescence in these systems was probed experimentally and computationally via time-dependent density functional theory (TD-DFT). The incorporation of Te into π-extended oligoacene frameworks was achieved by an efficient Zr/Te transmetalation protocol; related zirconium-element exchange reactions have been used to prepare both electron-rich and electron-deficient heterocycles containing different elements from throughout the p-block. Therefore, the current study provides a clear path to incorporate inorganic elements into heteroacenes of greater complexity and side group selectivity compared to existing synthetic routes.

Full text of DOI:10.1021/acs.inorgchem.9b02213

Article
Cite This: Inorg. Chem. XXXX, XXX, XXX−XXX
pubs.acs.org/IC
A Modular Approach to Phosphorescent π‑Extended Heteroacenes
†
†,‡
†
#
§
†
Emanuel Hupf, Yuki Tsuchiya, Wayne Moffat, Letian Xu, Masato Hirai, Yuqiao Zhou,
Michael J. Ferguson,† Robert McDonald, Toshiaki Murai, Gang He,* and Eric Rivard*
†
‡
,#
,†
†
Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
‡
Department of Chemistry and Biomolecular Science, Faculty of Engineering, Gifu University, Yanagido, Gifu 501-1193, Japan
Frontier Institute of Science and Technology, Xi’an Jiaotong University, Xi’an, Shaanxi Province 710054, China
Department of Chemistry, Graduate School of Science, Institute of Transformative Bio-Molecules (WPI-ITbM), and Integrated
#
§
Research Consortium on Chemical Sciences (IRCCS), Nagoya University, Furo, Chikusa, Nagoya 464-8602, Japan
*
S Supporting Information
ABSTRACT: A modular route to previously inaccessible classes of ring-fused π-
extended heteroacenes bearing the heavy inorganic element tellurium (Te) is
presented. These new materials can be viewed as n-doped analogs of molecular
graphene subunits that exhibit color tunable visible light phosphorescence in the
solid state and in the presence of air. The general mechanism of phosphorescence
in these systems was probed experimentally and computationally via time-
dependent density functional theory (TD-DFT). The incorporation of Te into π-
extended oligoacene frameworks was achieved by an efficient Zr/Te trans-
metalation protocol; related zirconium-element exchange reactions have been used
to prepare both electron-rich and electron-deficient heterocycles containing
different elements from throughout the p-block. Therefore, the current study
provides a clear path to incorporate inorganic elements into heteroacenes of greater
complexity and side group selectivity compared to existing synthetic routes.
1
INTRODUCTION
diphenyltellurophene is an effective singlet oxygen ( O )
2
6b
■
sensitizer.
The ongoing revolution in molecular electronics draws
substantially from newly emerging synthetic methods to gain
access to planar π-conjugated frameworks of controlled
A few years ago, our group prepared the bis(boryl)-
tellurophene III (Chart 1), the first tellurophene that is
phosphorescent in the solid state at room temperature. The
green emission in III stems from aggregation induced emission
3b
1
structure and function. Moreover, greatly expanded structural
variability and increasingly tunable optoelectronic properties,
such as improved charge transport and luminescence, become
possible with the incorporation of inorganic elements into π-
7
(
AIE) and is maintained even in the presence of oxygen, a
known quencher of phosphorescence. Since 2014, our team
has been able to prepare various phosphorescent tellurophenes
and benzotellurophenes (e.g., IV in Chart 1) of tunable
structure. Drawing inspiration from optoelectronically active
phenanthrene and pyrene systems, we now report a general
route to new two-dimensional monomeric and dimeric π-
extended heteroacenes featuring Te. In addition, we have been
able to incorporate configurationally locked cyclooctynes
within tellurophene heterocycles, leading to visible solid state
phosphorescence in air. The impressive generality of the
2
electron delocalized scaffolds. The presence of heavy main
group (p-block) elements also yields compounds with
enhanced spin−orbit coupling, which can lead to more
efficient phosphorescence, a highly sought property for
8
9
3
OLEDs. In this regard, tellurophene heterocycles, the heavier
element (Te) congeners of thiophenes, have garnered
considerable attention. Access to tellurophenes is often
thwarted by a lack of synthetic routes, however once obtained,
such species exhibit desirable properties such as small
4
10
zirconium-mediated ring assembly procedure described in
this article should greatly increase the number of electron-rich
2g,11
4b
HOMO−LUMO gaps (<1.3 eV) for photovoltaics. The
2a,3g
presence of Te encourages the formation of triplet excitons
(e.g., P, S, Se and Te)
and electron-deficient (e.g., B)
4e
(
electron−hole pairs), enabling long exciton diffusion lengths
heteroacenes that can be accessed/tailored for optoelectronic
applications. We also build upon our prior excited state (TD-
to present a general predictive
roadmap for the evaluation of new phosphorescent targets with
IR emission.
4e,f
and simplified (layered) solar cell device architectures.
8c,d,12
Chart 1 highlights various optoelectronically active Te-
heterocycles. For example, Detty and co-workers developed
the red fluorescent telluroxorhodamine I for bioimaging, and
DFT) computations
5
related compounds have been used as photooxidation
5
b
catalysts.
Diaryltellurophenes II show color tunable
Received: July 23, 2019
6a
fluorescence from blue to orange, while the parent 2,5-
©
XXXX American Chemical Society
A
DOI: 10.1021/acs.inorgchem.9b02213
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Article
Chart 1. Selected Known Luminescent Tellurophenes I−IV (Top) and New Class of Tellurophenes Introduced in This Work
(
Bottom)
Br
Scheme 1. Synthesis of 5- BenzoTe and BenzoTe-Oc
1
4
RESULTS AND DISCUSSION
2,2′-bipyridine) affords air- and moisture-stable phosphor-
escent Te heterocycles (Schemes 1−4).
■
At the onset, we sought to incorporate the following hallmarks
into our next generation tellurium-based heteroacenes (Chart
): (a) molecular rigidity for greater charge mobility and to
limit nonradiative energy loss during phosphorescence; (b)
attain air, moisture, and thermal stability within the resulting
inorganic heterocycles; (c) access new heteroacene motifs to
demonstrate a wide synthetic scope.
Br
The brominated benzotellurophenes 5- and 6- BenzoTe
Scheme 1) were first prepared as possible precursors to a new
polymer class, poly(benzotellurophenes) (vide infra). Starting
from the diarylzirconocene Cp Zr(p-BrC H ) (2),
heating this reagent (110 °C) in the presence of PinBC
CPh (BPin = pinacolboronate) in toluene led to the exclusive
formation of zirconacycles with the BPin group adjacent to the
ZrCp unit. However, due to the lack of regiocontrol during
Cp Zr−benzyne intermediate formation (via loss of BrPh),
a ca. 1:1 isomer mixture of 5- and 6- BenzoZrCp was
obtained, which could be separated by fractional crystalliza-
tion. Reaction of purified 5- BenzoZrCp with TeCl ·bipy
afforded the desired brominated tellurophene 5- BenzoTe in
56% isolated yield (Scheme 1).
(
1
15,16
2
6
4 2
Synthesis of Monomeric and Dimeric Ring-Fused
Telluroacenes and Substituent “Locked” Telluro-
phenes. All of the synthetic protocols reported in this paper
start with the formation of zirconacycles via alkyne coupling/
2
13b
2
Br
2
1
0,13
16
Br
insertion.
Once these air- and moisture-sensitive Zr
2 2
Br
precursors are obtained, efficient Fagan−Nugent Cp Zr/Te
2
5
−
transmetalation (Cp = η -C H ) with TeCl ·bipy (bipy =
5
5
2
B
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Scheme 2. Access to the Ring-Fused Heterocycle Oc-Te-Oc
Scheme 3. Synthesis of the Phenanthrene- and Pyrene-Fused Tellurophenes PhenTe and PyrTe
Chart 2. Alkyl-Tethered Dimeric Telluroacenes
1
6
Knowing that molecular rigidity is often key to enhancing
phosphorescence, two Te heterocycles bearing ring-fused
products PhenZrCp2 and PyrZrCp2. PhenZrCp2 and
PyrZrCp were then converted into the air- and moisture-
stable ring-fused tellurophenes PhenTe and PyrTe via Cp Zr/
Te transmetalation (Scheme 3). These telluraacenes could also
2
17
diarenecyclooctene units were prepared. Heating Cp ZrPh
2
2
2
1
8
(1) in the presence of the strained diarenecyclooctyne gave
the target benzozirconacycle BenzoZrCp -Oc, which was
readily converted into its respective tellurophene BenzoTe-
be covalently linked by an alkyl − (CH ) - tether (Chart 2) to
2
2 4
yield dimeric arrays. Motivation for this latter structural
modification arises from work by Yamaguchi and co-workers
who prepared linked anthracenyl dimers, leading to bath-
ochromically shifted emission for bioimaging, stemming from
Oc by treatment with TeCl ·bipy (Scheme 1). Coupling of two
2
19
diarenecyclooctyne units with Rosenthal’s reagent Cp Zr-
2
(
Me SiCCSiMe )(pyridine) eventually gave the substituent-
3 3
21
“locked” tellurophene Oc-Te-Oc (Scheme 2).
intramolecular “excimer” formation in solution. Accordingly,
the alkyl-linked dimeric Te−heteroacenes [BenzoTe] C ,
Lastly, we prepared Te-based heteroacenes built upon
2
4
benzo-, phenanthrene-, and pyrene-subunits. Fortunately, a
general route to these π-extended molecules was possible via a
tandem metalation (zirconation)/C−H activation protocol. As
an example, 9-lithiophenanthrene and 1-lithiopyrene (prepared
from the reaction of 9-bromophenanthrene and 1-bromopyr-
[PhenTe] C , and [PyrTe] C were each prepared from the
2 4 2 4
difunctional building block PinBCC(CH ) CCBPin via
2
4
sequential alkyne insertion and Zr/Te atom replacement steps
(cf. Scheme 3). Notably, tethering of the heteroacenes was also
expected to enhance luminescence efficiency in solution due to
a restriction in available molecular motion. Furthermore, TD-
DFT computations suggest that Te-orbital participation in the
excitation processes is one requirement for phosphorescence to
occur in these tellurophenes (vide infra). In order to further
probe the influence of the Te center in the excitation
n
enyl with BuLi, respectively) were each combined with
Cp ZrMeCl, in the presence of the alkyne PinBCCPh
2
20
(
Scheme 3). On the basis of prior work, this procedure likely
first affords a zirconacycle via C−H activation (and methane
loss) with subsequent alkyne insertion to yield the isolable
C
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properties, [BenzoTe] C was brominated using copper(II)
2
4
dibromide to afford the benzodibromotellurium(IV) dimer
BenzoTeBr ] C (eq 1).
[
2
2
4
Phosphorescence within π-Extended Telluroacenes.
As stated, phosphorescence can lead to highly efficient OLEDs,
however retaining emission in the solid state is challenging due
to self-quenching (triplet−triplet annihilation) and quenching
3
g
by O in air. By positioning boryl (−BPin) and “curved”
2
Figure 1. Emission spectra of [BenzoTe-Oc]·MeCN in the solid state
before (black line; λex = 360 nm) and after (blue line; λex = 360 nm)
grinding as well as drop casted film (red line; λex = 340 nm). Insets
show emission under irradiation at 360 nm with a hand-held UV-
lamp.
diarenecyclooctene (Oc) substituents onto our Te hetero-
cycles, a close intermolecular approach of the Te centers is
suppressed (>4.2 Å, i.e., outside the sum of the van der Waals
radii) leading to green to orange-red phosphorescence in the
16
solid state and in the presence of air (see Table S1). Despite
Br
the presence of a bromine atom in 5- BenzoTe, which could
increase the rate of intersystem crossing (kISC) to “spin-
2
2
forbidden” triplet states,
no substantial increase in
phosphorescence quantum yield (Φ = 1.4%) was found in
comparison to the known nonbrominated surrogate IV (Chart
8
a
Br
1
). Interestingly, BenzoTe underwent Suzuki−Miyaura
cross-coupling to yield low molecular weight poly-
(
benzotellurophene) poly[BenzoTe] (Scheme 4) as evidenced
8b
by MALDI-TOF analysis, however protodeboronation
dominated, resulting in very low (<10%) polymer yields with
Br
formation of BenzoTe-H as a contaminant (Scheme 4); the
resulting random copolymers were nonemissive.
Among the Te-heterocycles introduced in this study, the
bis(diarenecyclooctene)tellurophene Oc-Te-Oc shows the
highest phosphorescence quantum yield (Φ) in the solid
Figure 2. Molecular structure of [BenzoTe-Oc]·MeCN with
ellipsoids presented at a 30% probability level. All hydrogen atoms,
except for those in MeCN, are omitted for clarity. Dashed lines
indicate CH---arene contacts [2.857(4)−3.099(4) Å].
state and in air (Φ = 9.5%, λ = 560 nm, τ = 74.2 μs), likely
em
due to the rigid nature of the flanking cyclic side groups.
Notably, phosphorescence in Oc-Te-Oc is persistent even at
temperatures of up to 270 °C. BenzoTe-Oc is also
zoTe-Oc to THF, n-hexane, toluene, methanol, and dichloro-
methane vapor failed to yield any discernible change in
phosphorescence, revealing a degree of selectivity in the
vaporchromism.
phosphorescent showing orange emission (Φ = 0.2%, λ
=
em
23
6
30 nm, τ = 5.6 μs). Interestingly, crystals of [BenzoTe-Oc]·
MeCN display yellow phosphorescence (Φ = 0.6%, λ = 560
em
nm, τ = 3.2 μs), which change to orange upon grinding (Φ =
An existing challenge from our prior work on phosphor-
3b,e,12
0
.7%, λ = 610 nm, τ = 4.8 μs). Exposure of the ground
escent tellurium and bismuth (Bi) heterocycles
is the low
em
crystals to MeCN vapor re-establishes the orange emission.
molar absorptivities (ε < ca. 5000 L/mol·cm) in comparison to
chromophores found in leading solar cell and OLED
technologies. In the OLED community, the degree of
(
(
Figure 1). The X-ray structure of BenzoTe-Oc·MeCN
Figure 2) reveals close arene---H CCN contacts [2.857(4)
3
to 3.099(4) Å] which likely modulate the vaporchromism;
brightness from a luminogen is often estimated via ε ×
PL
π-extended subunits (e.g., pyrene) would enhance the
2
4
25
atoms-in-molecules (AIM) computations also identified
Φ , thus we hoped that incorporation of strongly absorbing
16
close CH···π(arene) interactions. Exposure of solid Ben-
Scheme 4. Synthesis of Oligomeric poly[BenzoTe]
D
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brightness of emission. Encouragingly, UV−vis data [Figure
nm, τ = 3.6 μs), while crystals grown from benzene, show
added solid state benzene CH---[BenzoTe] C contacts that
1
6
S20] on the dimers [PhenTe] C and [PyrTe] C , and the
2
4
2
4
2 4
pyrenyl monomer PyrTe in THF all yield intense absorptions
likely add rigidity to the system and affords much stronger
at 290−420 nm of ε = 85000 to 135000 L/mol·cm, with a
green emission [Φ = 1.1%; λ = 540 nm, τ = 50.6 μs; Figures
em
16
progressive red-shift in λ upon the incorporation of added
S26 and S35a]. As a final point, the pyrenyl-substituted
telluracenes PyrTe and [PyrTe] C (Chart 2, Figure 4) show
max
ring-fused arenes.
2
4
The dimeric tellurophene [PhenTe] C (Chart 2, Figure 3)
multiple intense absorption features in the 290−420 nm region
2
4
displays weak orange phosphorescence in the solid state in the
(in THF), yet excitation at different wavelengths (λ ) in this
ex
spectral region yields similar phosphorescence emission λem;
thus, one sees an “antenna-effect” where multiple different
(
and efficient) excitations lead to a single phosphorescence
emission event.
A different situation emerged when emission spectra of
various Te-heterocycles were measured in deoxygenated THF.
While no solution-phase photoluminescence was detected for
Br
the monomeric tellurophenes BenzoTe, BenzoTe-Oc, and
Oc-Te-Oc, the alkyl-linked dimers [BenzoTe] C , [Phen-
2
4
Te] C , and [PyrTe] C , as well as the pyrenyl monomer
2
4
2
4
PyrTe, all show phosphorescence with a gradual bathochromic
shift in λem [from 555 to 630 nm] with increasing arene-ring
content. Visually this is manifested in color changes from green
to orange to deep red with absolute quantum yields of 6.4%,
1
.6%, 1.0%, and 0.7% for [BenzoTe] C , [PhenTe] C ,
2 4 2 4
PyrTe, and [PyrTe] C , respectively (Figure 5 and Figure
2
4
1
6
S25a). The decreasing quantum yields for the longer
emission wavelengths matches what is expected from the
Energy Gap Law (i.e., increase in nonradiative decay rates k
nr
26
as the energy of emission decreases). PyrTe and [PyrTe] C4
2
show features due to vibronic coupling, while the emission
lifetimes for the dimeric telluroacenes were found to be in the
narrow range of 33.0 to 49.8 μs, consistent with phosphor-
escence; monomeric PyrTe shows a significantly longer
lifetime of τ = 259.0 μs. The phosphorescence of all three
tellurophene dimers and PyrTe is quenched upon exposure of
Figure 3. Molecular structure of [PhenTe] C with ellipsoids at a
2
4
30% probability level. Hydrogen atoms are omitted for clarity.
presence of air (Φ < 0.1%, λ = 600 nm, τ = 7.0 μs; Figure
em
1
6
S27 ), whereas [PyrTe] C is nonemissive. Of added note,
2
4
27
the benzotellurophene analogue [BenzoTe] C (Chart 2,
their solutions to air.
2
4
1
6
25
Figure S34a ) exhibits crystallization-enhanced emission as
Excimer formation within extended π-conjugated systems is
28
single crystals obtained by recrystallization from CHCl /n-
well-known, however no significant interarene π-stacking was
3
hexanes displays weak green emission (Φ < 0.1%, λem = 540
detected by X-ray crystallography for any of our new Te-
Figure 4. Molecular structure of [PyrTe] C with ellipsoids at a 30% probability level. Hydrogen atoms, as well as the cocrystallized benzene
2
4
solvates, are omitted for clarity.
E
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more rigid local environment about the telluroacenes at higher
22
loadings in PMMA. As a last point, excimer formation in
acenes is often observed and usually leads to broadening and a
28a
red-shift in the emission profile. However, for our examined
tellurophenes, the opposite trend occurs: more structured
emission bands and a slight blue-shift in λem are seen in the
solid state compared to the emission in solution; thus, excimer
formation is not likely.
TD-DFT Computations. Time-dependent density func-
tional theory (TD-DFT) computations were carried out for the
monomers BenzoTe-Oc, Oc-Te-Oc, PhenTe, and PyrTe as
well as for the three dimers [BenzoTe] C , [PhenTe] C , and
2
4
2
4
[
PyrTe] C . The computed absorption maxima at the B3LYP/
2 4
cc-pVTZ(-PP) level of theory are in agreement with the
experimental UV−vis data. Consistent among all of the
dimers in this study, the most intense components of the
Figure 5. Phosphorescence spectra of [BenzoTe] C (green; λ
=
16
2
4
ex
3
60 nm), [PhenTe] C (orange; λ = 340 nm) and [PyrTe] C (red;
2 4 ex 2 4
λex = 390 nm) in deoxygenated THF solutions (concentration = 1.0
μM). Insets show emission under irradiation (360 nm) with a hand-
held UV-lamp.
absorptions arise from significant orbital participation from Te
(
e.g., p-orbital), which is a key requirement in maximizing
spin−orbit coupling (SOC) and intersystem crossing (ISC) to
triplet excited states.
3
e,8c,d,12
Another general feature is
heterocycles, with the exception of the pyrene derivatives
localization of excitations within both the tellurophene and
adjacent acene subunits, with an added contribution to the
LUMO levels by C−B π-overlap involving the BPin group. In a
PyrTe and [PyrTe] C (π−π contacts = 3.45−3.70 Å, Figures
2
4
1
6
S33 and S37) The emission of PyrTe and [PyrTe] C have
2
4
also been studied at different wt % concentrations in drop-cast
films of poly(methyl methacrylate) (PMMA). Both com-
pounds show predominantly blue fluorescence at ca. 400 nm in
8c
benchmarking study on tellurophenes, it was found that the
B3LYP functional is suitable to accurately predict excitation
properties. However, a computational study involving pyrene
derivatives revealed that the B3LYP functional has issues in
accurately reproducing the correct order of excited states, with
1
wt % PMMA matrices with a very weak red phosphorescence
at 630−690 nm (PyrTe: Φ = 1.9%; [PyrTe] C : Φ = 1.0%).
2
4
In 10 wt % PMMA matrices, the red phosphorescence
becomes dominant (PyrTe, Φ = 0.3%; τ = 78.0 μs;
29
the CAM-B3LYP functional proving more suitable results.
630
Therefore, we repeated the TD-DFT computations of PhenTe
and PyrTe as well as the dimeric tellurophenes with the CAM-
B3LYP functional. In all studied cases, the CAM-B3LYP
predicted excitation energies are shifted to higher energies
compared to the B3LYP results and the order of excited states
does not differ between B3LYP and CAM-B3LYP for PhenTe,
PyrTe, and [PhenTe] C . For the dimers [BenzoTe] C and
[
PyrTe] C , Φ = 0.1%; nm, τ = 44.2 μs; Figure 6). An
2
4
630
explanation for this phenomenon could be the presence of a
2
4
2
4
[
PyrTe] C , the order of excited states differs between the two
2 4
functionals, but more importantly both functionals show the
importance of orbital participation of the tellurium atom(s) to
the transitions.
Another essential aspect needed for obtaining phosphor-
escence is the presence of energetically close singlet and triplet
excited states. Accordingly, all of the Te-heterocycles
investigated in this study show low-lying excited singlet states
16
that are within <0.1 eV in energy of excited triplet states,
thereby increasing the chance of intersystem crossing (ISC).
The computed differences of the zero-point corrected adiabatic
energies (E0−0) of the S and T states of the monomeric Te-
0
1
species and for the dimeric [PyrTe] C are in reasonable
2
4
agreement with the experimentally obtained phosphorescent
energies. Bigger deviations of up 0.80 to 0.83 eV have been
12b
obtained for [PhenTe] C and [BenzoTe] C .
2
4
2
4
As a bathochromic shift in emission maxima is seen with
increasing acene content, we investigated if larger π-conjugated
systems might shift the phosphorescence into the IR region.
For this purpose we computed the phosphorescence energies
of the benzo[a]pyrenyl-, dibenzo[a,e]pyrenyl-, and naphtho-
[
2,3-a]pyrenyl-substituted telluroacenes Benzo[a]PyrTe,
Dibenzo[a,e]PyrTe and Naphtho[2,3-a]PyrTe, respectively
Figure 7). Naphtho[2,3-a]PyrTe indeed shows a predicted
bathochromic shift of the phosphorescence energy to 1.37 eV
(
Figure 6. Photoluminescence spectra of [PyrTe] C in PMMA
2
4
matrices with 1 wt % (top) and 10 wt % (bottom). Insets show
photograph of the emission under illumination with a hand-held UV-
lamp (360 nm, excitation).
30
(902 nm), making this species a target for future exploration.
Notably, the lower predicted λem of Dibenzo[a,e]PyrTe (651
F
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Figure 7. Calculated zero-point energy (ZPE) corrected adiabatic energy difference between T and S (E0−0) at the B3LYP/cc-pVTZ-(PP) level of
1
0
theory given in eV (black) and nm (red), respectively, with R′ = BPin and R″ = Ph.
nm) indicates that the relative arrangement of the fused acene
rings has a significant impact on the emission maximum
Oakwood Chemicals and all other chemicals were purchased from
14
Sigma-Aldrich and were used as received. TeCl ·bipy, PhC
2
3
2
33
CBPin, PinBCC−C H −CCBPin, 5,6-didehydro-11,12-
(
despite the existence of the same number of fused rings as in
4
8
1
8
dihydrodibenzo[a,e]cyclooctyne,
Cp Zr(pyridine)-
2
36
Naphtho[2,3-a]PyrTe).
34
35
(
Me SiCCSiMe ), Cp ZrPh , and 1-bromopyrene were pre-
3 3 2 2
The requirement of the Te-atoms to be directly involved in
the excitation processes can also be probed experimentally by
1
11
1
13
1
pared according to literature procedures. H, B{ H}, and C{ H}
NMR spectra were recorded on a Varian Inova-400, Varian Inova-
31
oxidizing the Te(II) centers to Te(IV) and verifying the
impact on phosphorescence (eq 1). As expected, the
benzodibromotellurium(IV) dimer [BenzoTeBr ] C does
5
00, Bruker AVHD500 cryo, Bruker AV400, or Varian Inova-700
1
13
1
spectrometer and referenced externally to SiMe ( H, C{ H}), or
F B·Et O ( B{ H}). Elemental analyses were performed by the
4
1
1
1
2
2
4
3
2
not show any emission in degassed THF or in the solid
state. TD-DFT computations at the B3LYP/cc-pVTZ level of
theory indicate significantly less Te-orbital participation in the
transitions compared to the emissive telluraacenes presented in
Analytical and Instrumentation Laboratory at the University of
Alberta. Melting point values were obtained in sealed glass capillaries
in nitrogen using a MelTemp melting point apparatus. High
resolution mass spectra were obtained on an Agilent Technologies
6220 oaTOF (APPI), Bruker 9.4T Apex-Qe FTICR (MALDI), or
Kratos Analytical MS-50G (EI) spectrometer. UV−visible spectro-
scopic measurements were carried out with a Varian Cary 5000
spectrophotometer. Steady-state photoluminescence (PL) spectra,
emission lifetime (τ), and photoluminescence quantum yields (Φ) in
solution, in the solid state and in PMMA films were obtained by using
a Horiba PTI QuantaMaster 8075 fluorescence spectrophotometer.
For the PL and quantum yield measurements, the spectrophotometer
was equipped with a 75 W xenon lamp (and an integrating sphere for
the quantum yield measurements). For the emission lifetime values,
the spectrophotometer was equipped with a 75 W xenon flash lamp.
Solid samples were measured in glass capillaries mounted in a custom-
made solids holder. PMMA films were drop-cast onto quartz plates
from THF solutions. Long-pass and short-pass cutoff filters were used
in respect to the applied excitation wavelengths. All quantum yields
are reported as absolute values. The photoluminescence measure-
ments of drop-cast films were obtained using a Edinburgh FLS980
fluorescence spectrophotometer equipped with a xenon lamp
16
this study (Figure S46).
CONCLUSION
■
A versatile synthetic procedure was used to access new classes
of π-extended Te heteroacenes displaying phosphorescence in
the solid state (in air) as well as in solution. Hallmarks of our
systems include: tunable emission color, intense light
absorption (leading to brighter emission), and a nearly
limitless possibility to generate new heteroacenes via the
general Zr-element exchange reaction presented. We also show
a systematic red-shift in phosphorescence emission into the
near IR with the grafting of added arene units onto a Te
heterocycle. This trend was reproduced with our DFT
calculations, however one needs to note that the relative
placement of the acenes rings also dramatically impacts the
energy of phosphorescence. Accordingly, our DFT calculations
have identified a possible near IR emitting phosphor
Naphtho[2,3-a]PyrTe (Figure 7) that should be accessible
(
Xe900), a microsecond flash-lamp (μF900), and an integrating
sphere, respectively, with a front-face method.
Synthetic Procedures. Adapted Synthesis of Cp ZrMeCl.
35,37
30
2
using our general protocol, starting from a known precursor.
MeLi (1.6 M solution in Et O, 12.5 mL, 20 mmol) was added at −78
2
Finally, we have linked two emissive acene subunits via alkyl-
tethers, enabling us to spatially confine these emitters in all
phases. Future work will involve modifying the spacer length to
even further red-shift the emission via intermolecular excimer
°
C to a suspension of Cp ZrCl (2.92 g, 10.0 mmol) in 30 mL of
2
2 2
Et O. The resulting mixture was stirred at −78 °C for 2 h and warmed
up to room temperature and stirred for an additional 30 min. The
solvent was removed under reduced pressure and the residue was
extracted with hexanes (60 mL). After filtration, the filtrate was
evaporated to dryness to give 2.18 g (87% yield) of colorless
Cp ZrMe , which was dissolved in 20 mL of toluene. A solution of
2
1
formation, while the search for new tellurium-based
4
b−d
polymers
will continue.
2
2
trityl chloride (2.43 g, 8.71 mmol) in 20 mL of toluene was then
added at room temperature, and the resulting reaction mixture was
stirred under reflux for 72 h, after which time H NMR analysis of an
aliquot of the mixture indicated completion of the reaction. The
solvent was then removed in vacuo and the residue was washed with
EXPERIMENTAL SECTION
■
1
General Considerations. All reactions were performed using
standard Schlenk and glovebox (MBraun) techniques under a
nitrogen atmosphere. Solvents were dried and degassed using a
Grubbs-type solvent purification system manufactured by Innovative
Technology, Inc., and stored under an atmosphere of nitrogen prior
to use. 9-Bromophenanthrene and pyrene were obtained from
hexanes (6 × 10 mL) to give Cp ZrMeCl as a pale-yellow solid (2.36
2
g, 87% yield based on Cp ZrCl ). The analytical data are in
2
2
3
5,37
accordance with the literature.
G
DOI: 10.1021/acs.inorgchem.9b02213
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
3
4
Synthesis of Cp Zr(C H Br) . n-BuLi (2.5 M solution in n-hexanes,
ArH), 6.92−6.87 (m, 2H, ArH), 6.77 (dt, J = 7.4 Hz, J = 1.4
2
6
4
2
HH
HH
3
8
(
.00 mL, 20 mmol) was added to a solution of 1,4-dibromobenzene
5.08 g, 21.5 mmol) in 30 mL of THF at −78 °C. The reaction
mixture was stirred for 15 min and Cp ZrCl (2.93 g, 10.0 mmol) was
Hz, 1H, ArH), 6.66−6.64 (m, 1H, ArH), 6.62 (dd, J = 7.6 Hz,
HH
4
J
HH
= 1.2 Hz, 1H, ArH), 6.13 (s, 5H, CpH), 5.87 (s, 5H, CpH),
2
2
3.67−3.64 (m, 1H, CH ), 3.40−3.36 (m, 1H, CH ), 2.80−2.73 (m,
2
2
1
3
1
then added. The resulting mixture was stirred at −78 °C for an
additional 30 min and warmed up to room temperature overnight.
The solvent was removed under reduced pressure and toluene (10
mL) was added to the residue. After filtration through Celite, the
filtrate was evaporated to dryness in vacuo to give a light brown oil.
Recrystallization from toluene at −30 °C gave a pale orange solid after
2H, CH ). C{ H} NMR (125.7 MHz, C D ): δ [ppm] = 193.9
2
6
6
(qC), 185.0 (qC), 148.7 (qC), 148.3 (qC), 145.9 (qC), 141.9 (qC),
138.6 (qC), 136.5 (CH), 136.0 (qC), 130.6 (CH), 130.0 (CH), 129.4
(CH), 126.2 (CH), 125.9 (CH), 125.8 (CH), 125.6 (CH), 125.6
(CH),, 125.4 (CH) 124.3 (CH), 123.8 (CH), 112.7 (Cp), 112.6 (Cp),
35.9 (CH ), 33.8 (CH ). Anal. Calcd for C H Zr [%]: C, 76.60; H,
2
2
32 26
2
days. This solid was lyophilized three times with benzene (10 mL
5.22. Found: C, 72.51; H, 5.24. Despite multiple efforts analyses for
carbon content were consistently too low. For copies of the NMR
spectra of BenzoZrCp -Oc, see Figure S4a,b. HRMS (EI), m/z: calcd
for C H Zr, 500.1082; found, 500.1070 (Δ2.4 ppm). Mp: 186−192
portions) to yield Cp Zr(C H Br) as a yellow-brown solid (5.20 g,
2
6
4
2
1
3
9
8%). H NMR (499.8 MHz, C D ): δ [ppm] = 7.34 (d, J = 8.1
Hz, 4H, ArH), 6.88 (d, J = 8.1 Hz, 4H, ArH), 5.61 (s, 10H, Cp).
C{ H} NMR (125.7 MHz, C D ): δ [ppm] = 180.6 (qC, ZrC),
6
6
HH
2
3
HH
32 26
°C (dec.).
13
1
6
6
1
37.6 (CH), 129.8 (CH), 120.6 (BrC), 112.5 (Cp). Anal. Calcd for
Synthesis of BenzoTe-Oc. A solution of 5,6-didehydro-11,12-
dihydrodibenzo[a,e]cyclooctyne (103 mg, 504 μmol) in 20 mL of
toluene was added to a solution of Cp ZrPh (190 mg, 506 μmol) in
10 mL of toluene, and the reaction mixture was stirred under reflux
for 17 h. The mixture was filtered and the volatiles were removed
C H Br Zr [%]: C, 49.54; H, 3.40. Found: C, 50.17; H, 3.60. Mp:
2
2
18
2
1
12−115 °C.
Synthesis of 5- BenzoZrCp . A solution of Cp Zr(C H Br)
2
2
2
Br
2
2
6
5
(
3.36 g, 6.00 mmol) in toluene (20 mL) was added to a solution of
PinBCCPh (1.37 g, 6.00 mmol) in 10 mL of toluene and the
reaction mixture was stirred under reflux for 17 h. The mixture was
allowed to cool to room temperature and filtered through Celite.
Removal of the volatiles from the filtrate afforded a crude product,
from the filtrate in vacuo. THF (10 mL) and bipy·TeCl (189 mg, 532
2
μmol) were then added, and the reaction mixture was stirred at room
temperature for 21 h. The mixture was filtered through Celite, and the
volatiles were removed from the filtrate under vacuum. The residue
was extracted with 20 mL of hexanes and filtered. The filtrate was
dried in vacuo and copper(I) iodide (192 mg, 1.01 mmol) as well as
THF (10 mL) was added, and the mixture was stirred overnight to
Br
Br
containing 5- BenzoZr and 6- BenzoZr in a ratio of 53:47
1
(
according to H NMR spectroscopy). Separation of both isomers
was possible by recrystallization of the crude mixture from toluene/
Br
I
hexanes at −30 °C for 2 days, yielding orange crystals of 5- BenzoZr
remove residual bipy in form of an insoluble Cu −bipy complex. The
1
(
(
(
1
550 mg, 15%). H NMR (499.8 MHz, C D ): δ [ppm] = 7.35−7.32
volatiles were removed in vacuo, and 10 mL of benzene was added to
the residue. The mother liquor was filtered, and the volatiles were
removed from the filtrate in vacuo. The yellow residue was
6
6
m, 3H, benzoH and H ), 7.18−7.16 (m, 3H, benzoH and H ), 7.06
tt, J = 8.0 Hz, J = 1.3 Hz, 1H, p-H ), 6.30 (d, J = 7.4 Hz,
H, benzoH), 6.13 (s, 10H, Cp), 0.82 (s, 12H, CH3). C{ H} NMR
Ph
Ph
3
4
3
HH
HH
Ph
HH
1
3
1
recrystallized from acetonitrile/hexanes/Et O (1:1:1) at −30 °C
2
(
(
125.7 MHz, C D ): δ [ppm] = 183.7 (ZrC), 150.0 (C−Ph), 149.3
overnight to yield fine yellow needles of BenzoTe-Oc (74.0 mg, 36%)
6
6
1
ZrCC), 144.7 (i-C ), 137.4 (benzoCH), 129.1 (m-C ), 128.2 (o-
that were suitable for single-crystal X-ray crystallography. H NMR
Ph
Ph
3
C ), 128.0 (benzoCH), 127.0 (benzoCH), 126.2 (p-C ) 121.0 (Br-
C), 113.1 (CpC), 82.0 (OC), 24.8 (CH3). B{ H} NMR (128.3
MHz, C D ): δ [ppm] = 29.9 (br). Anal. Calcd for C H BBrO Zr
(499.8 MHz, CDCl ): δ [ppm] = 7.99 (d, J = 7.7 Hz, 1H, ArH),
Ph
Ph
3
HH
1
1
1
3
4
3
7.39 (dd, J = 8.0 Hz, J = 0.8 Hz, 1H, ArH), 7.32 (dt, J = 7.5
HH HH HH
4
3
Hz, J = 0.9 Hz, 1H, ArH), 7.28−7.26 (m, 1H, ArH), 7.22 (dt, J
6
6
30 30
2
HH
HH
4
[
%]: C, 59.61; H, 5.00. Found: C, 59.55; H, 5.15. Mp: 237−242 °C.
= 7.4 Hz, J = 1.3 Hz, 1H, ArH), 7.18−7.13 (m, 3H, ArH), 7.11−
HH
Br
Synthesis of 5- BenzoTe. THF (10 mL) was added to a mixture
7.06 (m, 4H, ArH), 3.26−3.14 (m, 2H, CH ), 2.96−2.85 (m, 2H,
2
Br
13
1
of 5- BenzoZr (135 mg, 268 μmol) and bipy·TeCl (101 mg, 285
CH ). C{ H} NMR (125.7 MHz, CDCl ): δ [ppm] = 148.1 (qC),
2
2
3
μmol). The reaction mixture was stirred at room temperature for 16 h
and filtered through Celite. After removal of the volatiles from the
filtrate, copper(I) iodide (57.4 mg, 301 μmol) as well as 10 mL of
THF were added. The mixture was stirred overnight to remove
residual bipyridine in the form of an insoluble CuI-bipy complex. The
volatiles were removed in vacuo and 10 mL of benzene was added.
The resulting mother liquor was filtered and the volatiles were
removed from the filtrate. Further purification by column
chromatography eluting from 100% hexanes to a hexanes:THF/5:1
145.8 (qC), 140.4 (qC), 139.9 (qC), 138.8 (qC), 138.4 (qC), 137.6
(qC), 133.5 (qC), 132.0 (CH), 130.4 (CH), 130.1 (CH), 129.8 (CH),
128.7 (CH), 127.6 (CH), 127.5 (CH), 125.8 (CH), 125.7 (CH),
125.3 (CH), 124.8 (CH), 34.5 (CH ), 33.9 (CH ). Anal. Calcd for
2
2
C H Te [%]: C, 64.77; H, 3.95. Found: C, 64.95; H, 4.09. HRMS
2
2
16
(EI), m/z: calcd for C H Te, 410.0314; found, 410.0313 (Δ0.2
2
2
16
ppm). Mp: 64−70 °C.
Synthesis of Oc-ZrCp -Oc. A solution of 5,6-didehydro-11,12-
2
dihydrodibenzo[a,e]cyclooctyne (89.2 mg, 437 μmol) in 5.0 mL of
Br
1
mixture gave 5- BenzoTe as a yellow solid (77.0 mg, 56%). H NMR
THF was added to a solution of Cp Zr(pyridine)(Me SiCCSiMe )
2
3
3
3
(
499.8 MHz, CDCl ): δ [ppm] = 7.85 (d, JHH = 8.3 Hz, 1H,
(89.7 mg, 220 mmol) in 5.0 mL of THF, and the reaction mixture was
stirred at room temperature for 17 h. The volatiles were then removed
3
4
benzoH), 7.60 (d, J = 1.9 Hz, 1H, benzoH), 7.43−7.42 (m, 3H,
HH
1
3
1
ArH), 7.34−7.32 (m, 3H, ArH), 1.17 (s, 12H, CH ). C{ H} NMR
in vacuo, and the residue was washed with of hexanes (2 × 10 mL) to
3
1
(
1
125.7 MHz, CDCl ): δ [ppm] = 156.2 (TeCC), 151.3 (Te−C),
give Oc-ZrCp -Oc as a pale orange solid (115 mg, 83%). H NMR
3
2
3
4
40.2 (C−Ph), 133.4 (benzoCH), 132.1 (benzoCH), 129.9 (m-CH or
(499.8 MHz, C D ): δ [ppm] = 7.17 (dd, J = 7.5 Hz, J = 2.1
6 6 HH HH
3
4
o-CH), 128.1 (CH), 127.8 (o-CH or m-CH), 127.5 (CH), 119.8
Hz, 2H, ArH), 6.93−6.90 (m, 4H, ArH), 6.83 (dt, J = 7.4 Hz, J
3 4
HH
HH
1
1
1
(
BrC), 84.1 (OC), 24.5 (CH3). B{ H} NMR (128.3 MHz, CDCl ):
= 1.3 Hz, 2H, ArH), 6.76 (dd, J = 7.6 Hz, J = 1.0 Hz, 2H,
3
HH HH
3
3
δ [ppm] = 31.4 (br). Anal. Calcd for C H BBrO Te [%]: C, 47.04;
ArH), 6.70 (t, J = 7.4 Hz, 2H, ArH), 6.66 (d, J = 7.4 Hz, 2H,
HH HH
ArH), 6.55 (dt, J = 7.4 Hz, J = 1.2 Hz, 2H, ArH), 6.09 (s, 10H,
2
0
20
2
3
4
H, 3.95. Found: C, 47.33; H, 3.92. HRMS (EI), m/z: calcd for
C H BBrO Te, 511.9788; found, 511.9781 (Δ1.4 ppm). Mp: 141−
HH HH
Cp), 4.01−3.95 (m, 2H, CH ), 3.60−3.55 (m, 2H, CH ), 2.94−2.90
20
20
2
2
2
1
3
1
1
43 °C.
(m, 2H, CH ), 2.86−2.80 (m, 2H, CH ). C{ H} NMR (125.7
MHz, C D ): δ [ppm] = 191.9 (qC), 149.3 (qC), 144.0 (qC), 143.3
2
2
Synthesis of BenzoZrCp -Oc. A solution of 5,6-didehydro-11,12-
2
6 6
dihydrodibenzo[a,e]cyclooctyne (33.1 mg, 162 μmol) in 10 mL of
toluene was added to a solution of Cp ZrPh (62.5 mg, 166 μmol) in
(qC), 136.8 (qC), 136.0 (qC), 130.0 (CH), 129.8 (CH), 128.4 (CH),
128.3 (CH), 126.1 (CH), 125.6 (CH), 125.5 (CH), 124.9 (CH),
124.1 (CH), 112.0 (Cp), 37.5 (CH ), 33.6 (CH ). Anal. Calcd for
2
2
10 mL of toluene, and the reaction mixture was stirred under reflux
2
2
for 15 h. The mixture was then filtered and the filtrate was evaporated
C H Zr [%]: C, 80.08; H, 5.44. Found: C, 80.13; H, 5.62. Mp:
42 34
to dryness in vacuo and recrystallized from toluene/hexanes at −30
260−264 °C (dec.).
1
°
C, to give BenzoZrCp -Oc as a yellow powder (38.7 mg, 48%). H
Synthesis of Oc-Te-Oc. THF (10 mL) was added to a mixture of
Oc-ZrCp -Oc (115 mg, 183 μmol) and bipy·TeCl (67.4 g, 190
2
NMR (499.8 MHz, C D ): δ [ppm] = 7.13−7.11 (m, 1H, ArH), 7.06
dd, J = 7.5 Hz, J = 1.1 Hz, 1H, ArH), 7.03−6.95 (m, 5H,
6
6
2
2
3
4
(
μmol), and the reaction mixture was stirred at room temperature for
HH
HH
H
DOI: 10.1021/acs.inorgchem.9b02213
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
2
0 h. The mixture was then filtered, and the volatiles were removed
143.6 (qC), 134.7 (qC), 133.3 (qC), 131.4 (qC), 130.6 (CH), 130.1
(CH), 128.6 (qC), 128.3 (CH), 128.3 (CH), 127.7 (CH), 127.5
(CH), 127.2 (CH), 125.9 (CH), 125.9 (CH), 125.7 (CH), 123.7
from the filtrate. The residue was then washed with 10 mL of hexanes
and dried. Further purification of the product was accomplished by
column chromatography starting with hexanes:THF/10:1, followed
by hexanes:THF/5:1, followed by 100% THF and 100% CH Cl as
1
1
(CH), 123.5 (CH), 83.7 (OC), 24.5 (CH3). B NMR (128.3 MHz,
C D ): δ [ppm] = 30.5 (br). Anal. Calcd for C H BO Te [%]: C,
2
2
6
6
28 25
2
eluants. The volatiles were removed in vacuo, and the residue was
recrystallized from a mixture of CHCl3 and MeOH at room
temperature to give Oc-Te-Oc as an orange solid (10.0 mg, 10%).
63.23; H, 4.74. Found: C, 63.53; H, 5.00. HRMS: calcd for
1
1
130
+
C H BO2 Te [M] , 534.1010; found, 534.1003 (Δ1.3 ppm).
28
25
Mp: 184 °C.
1
4
3
H NMR (399.8 MHz, CDCl ): δ [ppm] = 7.33 (dd, J = 6.8 Hz,
Synthesis of PyrZrCp . n-Butyllithium (2.5 M in hexanes, 0.28 mL,
3
HH
2
3
JHH = 1.5 Hz, 2H, ArH), 7.17−7.07 (m, 6H, ArH), 7.02 (d, J
=
710 μmol) was added to a solution of 1-bromopyrene (200 mg, 712
μmol) in 4 mL of THF at −78 °C. The reaction mixture was stirred
for 1 h, giving rise to a yellow suspension. This mixture was warmed
HH
3
4
7
6
.5 Hz, 2H, ArH), 6.90 (td, J = 7.5 Hz, J = 1.3 Hz, 2H, ArH),
HH HH
3
4
3
.72 (td, J = 7.5 Hz, J = 1.1 Hz, 2H, ArH), 6.50 (dd, J = 7.7
Hz, J = 1.1 Hz, 2H, ArH), 3.55−3.41 (m, 4H, CH ), 3.09−2.98
m, 4H, CH2). C{ H} NMR (125.7 MHz, CDCl ): δ [ppm] =
HH
HH
HH
4
to room temperature, and then a solution of Cp ZrMeCl (194 mg,
HH
2
2
13
1
(
712 μmol) in 5 mL of toluene was added, to yield a red colored
mixture. After 5 min, a solution of PinBCCPh (162 mg, 712 μmol)
in 5 mL of toluene was added, resulting in a color change from red to
yellow. Stirring was continued at room temperature for 30 min, after
which the reaction mixture was heated to reflux with stirring
overnight. The reaction mixture was then cooled to room temperature
and filtered, and the solvent volume of the filtrate was reduced to 2
mL. The product was precipitated by addition of 10 mL of hexanes,
3
1
49.6 (qC), 142.9 (qC), 140.7 (qC), 140.2 (qC), 139.6 (qC), 138.8
(qC), 132.5 (CH), 131.1 (CH), 130.5 (qC), 130.0 (CH), 129.4 (CH),
1
1
29.3 (CH), 127.4 (CH), 127.4 (CH), 126.6 (CH), 126.5 (CH),
25.7 (CH), 125.2 (CH), 125.1 (CH), 34.7 (CH ), 34.6 (CH ), 33.0
2
2
(
6
CH ). Anal. Calcd for C H Te [%]: C, 71.69; H, 4.51. Found: C,
2.97; H, 5.10. Despite multiple efforts analyses for carbon content
2 32 24
were consistently too low. For copies of the NMR spectra of Oc-Te-
1
24
30
+
Oc, see Figures S7a-S7b. HRMS (EI): calcd for C H
Te [M] ,
and PyrZrCp was recovered and dried to give a yellow solid (339
2
3
2
1
3
5
38.09406; found, 538.09439 (Δ0.6 ppm). Mp: 292 °C (decomp.).
mg, 75%). H NMR (499.7 MHz, C
7.1 Hz, 1H, PyrH), 7.93−7.90 (m, 3H, PyrH), 7.78 (t, JHH = 7.6 Hz,
1H, PyrH), 7.67 (d, JHH = 8.9 Hz, 1H, PyrH), 7.59 (dd, JHH = 8.1
Hz, JHH = 1.3 Hz, 1H, PhH), 7.52 (d, JHH = 8.9 Hz, 1H, PyrH), 7.37
(t, JHH = 7.7 Hz, 2H, PhH), 7.24 (tt, JHH = 7.5 Hz, JHH = 1.3 Hz,
1H, PhH), 6.61 (d, JHH = 8.9 Hz, 1H, PyrH), 6.33 (s, 10H, CpH),
0.92 (s, 12H, CH ). C{ H} NMR (125.7 MHz, C D ): δ [ppm] =
D ): δ [ppm] = 8.01 (d, JHH =
6 6
3
Synthesis of PhenZrCp . n-Butyllithium (2.5 M in hexanes, 0.31
2
3
3
mL, 0.78 mmol) was added to a solution of 9-bromophenanthrene
0.200 g, 0.778 mmol) in 5 mL of THF at −78 °C. The reaction
mixture was stirred for 1 h, and a solution of Cp ZrMeCl (0.211 g,
4
3
(
3
3
4
2
3
0.778 mmol) in 2 mL of toluene was added at the same temperature.
1
3
1
After 5 min, a solution of PinBCCPh (0.117 g, 0.389 mmol) in 5
mL of toluene was added. The reaction mixture was allowed to warm
up to room temperature, and stirring was continued for 30 min, after
which the reaction mixture was heated to reflux with stirring
overnight. The reaction mixture was then cooled to room temper-
ature, filtered and the volume of the filtrate was reduced in vacuo to
approximately 2 mL. Then 10 mL of hexanes was added, and the
mixture was subsequently filtered. Storage of the filtrate at room
temperature overnight gave red crystals of PhenZrCp2 that were
3
6
6
185.7 (qC), 148.8 (qC), 145.8 (qC), 144.7 (qC), 139.0 (qC), 132.2
(qC), 131.5 (qC), 130.9 (qC), 130.6 (CH), 129.6 (CH), 129.1 (CH),
128.1 (CH), 126.2 (CH), 126.1 (CH), 126.0 (CH), 125.9 (qC), 125.4
(CH), 124.6 (CH), 124.1 (CH), 123.7 (qC), 122.7 (CH), 112.8 (Cp),
1
1
1
82.1 (OC), 24.9 (CH
). B{ H} NMR (128.3 MHz, C
D ): δ [ppm]
6 6
3
= 24.6 (br). Anal. Calcd for C40
H35BO
Zr [%]: C, 73.94; H, 5.43.
2
Found: C, 70.41; H, 5.64. Despite multiple efforts analyses for carbon
content were consistently too low. For copies of the NMR spectra of
1
suitable for X-ray crystallography (155.5 mg, 32%). H NMR (499.7
PyrZrCp
Synthesis of PyrTe. bipy·TeCl
a solution of PyrZrCp (100 mg, 154 μmol) in 10 mL of THF, and
2
, see Figure S10a−d. Mp: 128 °C (dec.).
3
MHz, C D ): δ [ppm] = 8.63−8.61 (m, 1H, ArH), 8.57 (d, J = 8.1
2
(54.6 mg, 235 μmol) was added to
6
6
HH
3
4
Hz, 1H, ArH), 7.83 (dd, J = 8.5 Hz, J = 0.8 Hz, 1H, ArH),
.48−7.46 (m, 2H, ArH), 7.35 (dd, J = 8.3 Hz, J = 1.4 Hz, 2H,
ArH), 7.23 (ddd, J = 7.5 Hz, J = 7.0 Hz, J = 1.1 Hz, 1H,
2
HH
HH
3
4
7
the reaction mixture was stirred at room temperature for 12 h. The
mixture was then filtered, and the volatiles were removed from the
filtrate. The residue was extracted with a 1:9 mixture of THF/hexanes
(10 mL) and filtered. The filtrate was filtered again through a plug of
silica (3 cm), and the filtrate was evaporated to dryness in vacuo to
give a yellow oil. This oil was triturated with 2 mL of hexanes to afford
yellow crystals of PyrTe. The supernatant was decanted after 12 h,
HH
HH
3
3
4
HH
HH
HH
3
ArH), 7.13 (d, J = 7.7 Hz, 2H, ArH), 7.07−7.03 (m, 2H, ArH),
HH
6
.38−6.36 (m, 1H, ArH), 6.24 (s, 10H, CpH), 1.02 (s, 12H, CH ).
3
1
3
1
C{ H} NMR (125.7 MHz, C D ): δ [ppm] = 184.7 (qC), 149.5
6
6
(
1
qC), 145.6 (qC), 140.2 (qC), 138.9 (qC), 132.0 (qC), 130.9 (CH),
30.2 (qC), 129.7 (qC), 128.4 (CH), 128.4 (CH), 127.6 (CH), 125.5
CH), 125.2 (CH), 125.1 (CH), 124.7 (CH), 124.5 (CH),, 123.3
1
(
(
and the crystalline PyrTe was dried in vacuo (23.8 mg, 28%). H
1
1
1
CH) 123.2 (CH), 112.4 (Cp), 25.2 (CH3). B{ H} NMR (128.3
NMR (499.8 MHz, CDCl ): δ [ppm] = 8.21 (s, 1H, PyrH), 8.20 (d,
3
3
3
MHz, C D ): δ [ppm] = 30.6 (br). Anal. Calcd for C H BO Zr [%]:
JHH = 7.8 Hz, 1H, PyrH), 8.18 (d, JHH = 8.9 Hz, 1H, PyrH), 8.12
(dd, JHH = 7.5 Hz, JHH = 0.8 Hz, 1H, PyrH), 8.00 (d, JHH = 8.8 Hz,
6
6
38 35
2
3
4
3
C, 72.94; H, 5.64. Found: C, 72.81; H, 6.09. Mp: 158−166 °C.
3
Synthesis of PhenTe. bipy·TeCl (56.7 mg, 160 μmol) was added
1H, PyrH), 7.98 (t, JHH = 7.6 Hz, 1H, PyrH), 7.55−7.51 (m, 5H,
2
1
3
1
to a solution of PhenZrCp (100 mg, 160 μmol) in 10 mL of THF,
PhH), 1.23 (s, 12H, CH ). C{ H} NMR (125.7 MHz, CDCl ): δ
3
3
2
and the reaction mixture was stirred at room temperature for 12 h.
The mixture was then filtered, and the volatiles were removed from
the filtrate in vacuo. The residue was then extracted with a 1:9 mixture
of THF/hexanes (10 mL) and filtered. The filtrate was filtered again
through a plug of silica (3 cm) and the solvent evaporated to dryness
to give a pale-yellow oil. This oil was triturated with 2 mL of hexanes,
which initiated the formation of pale-yellow crystals of PhenTe. The
supernatant was then decanted after 12 h and crystalline PhenTe was
[ppm] = 159.6 (qC), 147.9 (qC), 141.2 (qC), 135.0 (qC), 133.2
(qC), 131.7 (qC), 131.6 (qC), 130.3 (CH), 129.8 (qC), 129.3 (CH),
128.2 (CH), 128.2 (CH), 127.9 (CH), 127.5 (CH), 126.9 (CH),
126.0 (CH), 125.8 (CH), 125.4 (CH), 125.0 (CH), 124.7 (qC), 122.3
1
1
(qC), 84.2 (OC), 24.6 (CH
). B NMR (128.3 MHz, CDCl ): δ
3
3
[ppm] = 32.3 (br). Anal. Calcd for C H BO Te [%]: C, 64.81; H,
3
0
25
2
4.53. Found: C, 64.63; H, 4.60. HRMS (EI): calcd for
1
1
130
+
C H BO2 Te [M] , 558.10101; found, 558.10084 (Δ0.3 ppm).
3
0
25
1
dried in vacuo (55.6 mg, 65%). H NMR (699.8 MHz, C D ): δ
Mp: 204 °C.
6
6
3
3
[
ppm] = 8.45 (d, J = 8.2 Hz, 1H, PhenH), 8.36 (d, J = 8.3 Hz,
H, PhenH), 7.89 (dd, J = 8.5 Hz, J = 0.8 Hz, 1H, PhenH),
.72 (dd, J = 7.9 Hz, J = 0.8 Hz, 1H, PhenH), 7.39−7.38 (m,
H, PhH), 7.34 (ddd, J = 8.2 Hz, J = 7.1 Hz, J = 1.2 Hz,
H, PhenH), 7.31−7.23 (m, 4H, PhH and PhenH), 7.19 (ddd, J
.0 Hz, J = 7.1 Hz, J = 1.1 Hz, 1H, PhenH), 7.06 (ddd, J
.4 Hz, J = 6.9 Hz, J = 1.3 Hz, 1H, PhenH). C{ H} NMR
Synthesis of [BenzoZrCp ] C . Cp ZrPh (200 mg, 0.532 mmol)
HH
HH
2 2
4
2
2
3
4
1
7
2
1
8
8
was dissolved in 5 mL of toluene, a solution of PinBCC(CH ) C
HH
HH
2 4
3
4
CBPin (95.0 g, 0.266 mmol) in 2 mL of toluene was added, and the
reaction mixture was stirred under reflux overnight. The reaction
mixture was filtered through Celite, and the volatiles were removed
from the filtrate in vacuo. The resulting yellow residue was washed
with hexanes (2 × 20 mL) and dried in vacuo to afford
HH
HH
3
3
4
HH
HH
HH
3
=
=
HH
3
4
3
HH
HH
HH
3
4
13
1
HH
HH
1
(
125.7 MHz, C D ): δ [ppm] = 160.9 (qC), 145.7 (qC), 145.5 (qC),
[BenzoZrCp ] C as a yellow solid (126 mg, 49%). H NMR
6
6
2 2 4
I
DOI: 10.1021/acs.inorgchem.9b02213
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
3
1
(
7
7
699.8 MHz, C D ): δ [ppm] = 7.44 (d, J = 7.8 Hz, 2H, ArH),
solid (26.6 mg, 23%). H NMR (699.8 MHz, CDCl ): δ [ppm] =
3
6
6
HH
3
4
3
3
3
.16 (ddd, J = 7.6 Hz, J = 1.5 Hz, 2H, ArH), 7.05 (ddd, J
.1 Hz, J = 6.9 Hz, J = 0.8 Hz, 2H, ArH), 6.62 (dd, J = 6.9
Hz, J = 1.3 Hz, 2H, ArH), 6.17 (s, 20H, CpH), 2.79 (m, 4H,
CH ), 1.96 (m, 4H, CH ), 1.06 (s, 24H, CH ). C{ H} NMR (176.0
MHz, C D ): δ [ppm] = 187.9 (qC), 154.5 (qC), 147.1 (qC), 136.0
CH), 125.7 (CH), 124.2 (CH), 123.5 (CH), 112.7 (CpC), 81.7
=
8.74 (d, J = 7.9 Hz, 2H, ArH), 8.70 (d, J = 8.4 Hz, 2H, ArH),
HH
HH
HH
HH HH
3
4
3
3
3
8.62 (d, J = 8.2 Hz, 2H, ArH), 7.81 (d, J = 7.9 Hz, 2H, ArH),
HH HH
7.63 (ddd, JHH = 8.2 Hz, JHH = 7.0 Hz, JHH = 1.1 Hz, 2H, ArH),
HH
HH
HH
4
3
3
4
HH
1
3
1
3
3
4
7.63 (ddd, JHH = 7.9 Hz, JHH = 7.5 Hz, JHH = 0.9 Hz, 2H, ArH),
7.54−7.50 (m, 4H, ArH), 3.67−3.65 (m, 4H, CH ), 2.09−2.06 (m,
). C{ H} NMR (176.0 MHz, CDCl ):
2
2
3
6
6
2
1
3
1
(
(
4H, CH
2
), 1.25 (s, 24H, CH
3
3
1
1
OC), 38.0 (CH ), 31.3 (CH ), 25.1 (CH ). B NMR (128.3 MHz,
δ [ppm] = 162.2 (qC), 164.2 (qC), 143.5 (qC), 134.6 (qC), 132.9
(qC), 130.8 (qC), 130.5 (CH), 127.8 (qC), 127.5 (CH), 127.3 (CH),
126.4 (CH), 125.4 (CH), 124.2 (CH), 123.7 (CH), 123.1 (CH), 84.0
2
2
3
C D ): δ [ppm] = 29.6 (br). Anal. Calcd for C H B O Zr [%]: C,
6
6
52 60
2
4
2
6
5.53; H, 6.35. Found: C, 64.86; H, 6.52. Mp: 118 °C (dec.).
1
1
Synthesis of [BenzoTe] C . bipy·TeCl (112 mg, 0.316 mmol) was
(OC), 36.8 (CH
CDCl ): δ [ppm] = 32.2. Anal. Calcd for C48
59.70; H, 5.01. Found: C, 60.44; H, 4.98. HRMS (APPI): calcd for
2
), 30.6 (CH ), 24.8 (CH
2 3
). B NMR (128.3 MHz,
2
4
2
added to a solution of [BenzoZrCp ] C (126 mg, 0.132 mmol) in 5
3
H
B
48
2
O
4
Te [%]: C,
2
2
2
4
mL of THF, and the reaction mixture was stirred at room temperature
for 12 h. After removal of all volatiles, the residue was washed with 20
mL of hexanes and dried in vacuo. The resulting residue was extracted
with 20 mL of benzene and filtered through a silica plug (3 cm).
Removal of the solvent from the filtrate gave [BenzoTe] C as a pale
yellow solid (37.5 mg, 37%). Crystals suitable for X-ray crystallog-
raphy could be obtained either by slow evaporation of benzene
leading to cocrystallized benzene) or from a CHCl /hexanes mixture
at room temperature (leading to a solvent free crystal structure). H
NMR (499.8 MHz, CDCl ): δ [ppm] = 8.00 (d, J = 7.8 Hz, 2H,
ArH), 7.83 (d, J = 8.0 Hz, 2H, ArH), 7.40 (ddd, J = 8.1 Hz,
+
C H B O Te [M + H] , 971.1959; found, 971.1943 (Δ1.7 ppm).
48 49 2 4 2
Mp: 190 °C (dec.).
Synthesis of [PyrZrCp ] C . n-BuLi (2.5 M in hexanes, 0.29 mL,
2 2 4
0.74 mmol) was added to a solution of 1-bromopyrene (207 mg,
.736 mmol) in 4 mL of THF at −78 °C. The reaction mixture was
stirred for 1 h giving rise to a yellow suspension. A solution of
Cp ZrMeCl (200 mg, 0.778 mmol) in 5 mL of toluene was added at
the same temperature, leading to the formation of a red mixture. After
2
4
0
(
2
3
1
3
5
min a solution of PinBCC(CH ) CCBPin (132 mg, 0.368
2 4
3
HH
3
3
mmol) in 5 mL of toluene was added, resulting in a color change from
red to yellow. The reaction mixture was allowed to warm to room
temperature, and stirring was continued for 30 min, after which the
mixture was heated to reflux with stirring overnight. The reaction
mixture was cooled to room temperature and filtered, and the solvent
was removed from the filtrate in vacuo to dryness to give a yellow oil.
This oil was then washed with hexanes (2 × 10 mL) and then washed
with a mixture of toluene/hexanes (1:4, 2 × 5 mL). The remaining
solid was dried in vacuo to give [PyrZrCp ] C as a yellow solid
HH
HH
3
3
4
3
JHH = 7.1 Hz, J = 1.0 Hz, 2H, ArH), 7.25 (ddd, J = 8.0 Hz,
HH
HH
4
JHH = 7.4 Hz, J = 1.1 Hz, 2H, ArH), 3.18−3.16 (m, 4H, CH ),
HH
2
1
3
1
1
.78−1.75 (m, 4H, CH ), 1.27 (s, 24H, CH ). C{ H} NMR (125.7
2
3
MHz, CDCl ): δ [ppm] = 158.8 (qC), 149.3 (qC), 135.7 (qC), 132.6
3
(
3
3
CH), 127.6 (CH), 125.2 (CH), 124.6 (CH), 83.9 (OC), 32.8 (CH ),
0.9 (CH ), 24.8 (CH ). B NMR (128.3 MHz, CDCl ): δ [ppm] =
2 3 3
2
1
1
1.8 (br). Anal. Calcd for C H B O Te [%]: C, 50.21; H, 5.27.
3
2
40
2
4
2
2
D
2 4
Found: C, 50.20; H, 5.24. HRMS (APPI): calcd for C H B O Te
M + H] , 771.1325; found, 771.1320 (Δ0.7 ppm). Mp: 166 °C
3
2
41
2
4
2
1
+
(219.3 mg, 50%). H NMR (499.8 MHz, C
6
6
): δ [ppm] = 8.25 (s,
[
(
3
3
2
2
2
2
3
H, ArH), 8.03 (d, J = 7.4 Hz, 2H, ArH), 7.99 (d, J = 7.2 Hz,
HH
HH
dec.).
3
3
H, ArH), 7.86 (d, J = 9.0 Hz, 2H, ArH), 7.82 (t, J = 7.6 Hz,
HH
HH
Synthesis of [PhenZrCp ] C . n-BuLi (2.5 M in hexanes, 0.31 mL,
.78 mmol) was added to a solution of 9-bromophenanthrene (0.200
g, 0.778 mmol) in 5 mL of THF at −78 °C. The reaction mixture was
stirred for 1.5 h and a solution of Cp ZrMeCl (0.211 g, 0.778 mmol)
2
2
4
3
3
H, ArH), 7.77 (d, J = 8.9 Hz, 2H, ArH), 7.67 (d, J = 8.9 Hz,
HH
HH
0
3
H, ArH), 6.51 (d, J = 8.9 Hz, 2H, ArH), 6.24 (s, 20H, CpH),
HH
.13−3.05 (m, 4H, CH ), 2.29−2.21 (m, 4H, CH ), 0.95 (s, 24H,
2
2
2
13
1
CH ). C{ H} NMR (125.7 MHz, C D ): δ [ppm] = 187.6 (qC),
3
6
6
in 5 mL of toluene (5 mL) was added at the same temperature. After
1
(
50.0 (qC), 144.3 (qC), 138.9 (qC), 132.2 (qC), 131.5 (qC), 131.0
qC), 130.7 (CH), 129.2 (CH), 128.3 (CH), 125.9 (qC), 125.8 (CH),
25.3 (CH), 124.3 (CH), 123.9 (CH), 123.7 (qC), 120.2 (CH), 112.6
5
min a solution of PinBCC(CH ) CCBPin (0.139 g, 0.389
2
4
mmol) in 5 mL of toluene was added. The reaction mixture was
warmed to room temperature and stirring was continued at room
temperature for 30 min, after which the mixture was heated to reflux
with stirring overnight. The reaction mixture was then cooled to room
temperature, filtered and the volatiles were removed from the filtrate
in vacuo to yield a red oil. This oil was washed with hexanes (3 × 10
mL), a mixture of toluene/hexanes (1:4, 10 mL) and then the
1
(
11
1
Cp), 81.9 (OC), 38.8 (CH ), 31.0 (CH ), 24.9 (CH ). B{ H}
2 2 3
NMR (128.3 MHz, C D ): δ [ppm] = 24.7 (br). Anal. Calcd for
6
6
C H B O Zr [%]: C, 71.98; H, 5.71. Found: C, 71.49; H,5.77. Mp:
7
2
68
2
4
2
250 °C (dec.).
Synthesis of [PyrTe] C . bipy·TeCl (84.0 mg, 237 μmol) was
added to a solution of [PyrZrCp ] C (100 mg, 83.2 μmol) in 10 mL
2
4
2
2
2 4
resulting precipitated solid was dried in vacuo to give
PhenZrCp ] C as an orange solid (0.176 g, 39%). H NMR
of THF, and the reaction mixture was stirred for 48 h and filtered
through Celite. After removal of the volatiles from the filtrate, the
remaining residue was washed with benzene (2 × 10 mL) and dried in
vacuo. The product was then extracted with 10 mL of chloroform and
filtered through a silica plug (3 cm); removal of the volatiles from the
filtrate then gave [PyrTe] C as a dark yellow solid (36.5 mg, 43%).
Crystals suitable for X-ray crystallography were obtained by slow
evaporation of a saturated benzene solution. It should be noted that
this method yields only a few single-crystals as the solubility of
1
[
2
2 4
(
699.7 MHz, C D ): δ [ppm] = 8.56−8.55 (m, 2H, ArH), 8.53 (d,
6
6
3
3
J
= 7.9 Hz, 2H, ArH), 8.15 (d, J = 8.1 Hz, 2H, ArH), 7.49−
HH
HH
3 3 4
7
1
.45 (m, 4H, ArH), 7.34 (ddd, J = 8.1 Hz, J = 7.5 Hz, J
=
HH
HH
HH
3
3
4
.1 Hz, 2H, ArH), 7.29 (ddd, J = 8.1 Hz, J = 7.5 Hz, J = 1.2
HH
HH
HH
2
4
Hz, 2H, ArH), 6.60−6.58 (m, 2H, ArH), 6.06 (s, 20H, CpH), 3.08−
3
.06 (m, 4H, CH ), 1.63−1.61 (m, 4H, CH ), 1.09 (s, 24H, CH ).
2
2
3
13
1
C{ H} NMR (176.0 MHz, C D ): δ [ppm] = 183.4 (qC), 149.3
6
6
1
(
1
(
3
[
5
qC), 140.3 (qC), 137.5 (qC), 131.8 (qC), 131.6 (CH), 129.5 (qC),
29.4 (qC), 127.0 (CH), 125.6 (CH), 125.0 (CH), 124.9 (CH), 124.6
CH), 123.6 (CH), 123.1 (CH), 111.8 (Cp), 81.9 (OC), 41.2 (CH ),
3.8 (CH ), 25.1 (CH ). B{ H} NMR (159.8 MHz, C D ): δ
ppm] = 24.2 (br). Anal. Calcd for C H B O Zr [%]: C, 70.81; H,
[PyrTe] C in benzene is very low. H NMR (499.8 MHz, CDCl ): δ
[ppm] = 8.48 (s, 2H, ArH), 8.15 (d, J = 7.7 Hz, 2H, ArH), 8.12
(d, J = 7.2 Hz, 2H, ArH), 8.05 (d, J = 8.9 Hz, 2H, ArH), 8.04
HH HH
2
4
3
3
HH
3
3
2
1
1
1
3
3
2
3
6
6
(d, J = 9.0 Hz, 2H, ArH), 7.98 (t, J = 7.6 Hz, 2H, ArH), 7.96
HH HH
3
6
8
68
2
4
2
(d, J = 9.0 Hz, 2H, ArH), 3.51−3.45 (m, 4H, CH ), 2.04−1.97
HH
2
13 1
.94. Found: C, 69.85; H,6.01. Mp: 138 °C (dec.).
(m, 4H, CH ), 1.26 (s, 24H, CH ). C{ H} NMR (125.7 MHz,
2
3
Synthesis of [PhenTe] C . bipy·TeCl (85.0 mg, 0.25 mmol) was
CDCl ): δ [ppm] = 159.8 (qC), 147.7 (qC), 135.9 (qC), 133.3 (qC),
2
4
2
3
added to a solution of [PhenZrCp ] C (137 mg, 0.12 mmol) in 10
131.7 (qC), 131.6 (qC), 129.7 (qC), 129.5 (CH), 128.3 (CH), 127.9
(CH), 126.8 (CH), 125.9 (CH), 125.4 (CH), 124.8 (CH), 124.7
(qC), 123.8 (CH), 122.2 (qC), 84.1 (OC), 33.2 (CH ), 30.5 (CH ),
2
2 4
mL of THF, and the reaction mixture was stirred at room temperature
for 12 h. The mixture was then filtered through Celite, the volatiles
removed from the filtrate, and the residue was washed with hexanes
2
2
1
1
24.9 (CH3). B NMR (128.3 MHz, CDCl ): δ [ppm] = 31.3 (br).
3
(20 mL) and dried. The resulting residue was extracted with 20 mL of
Anal. Calcd for C H B O Te [%]: C, 61.61; H, 4.77. Found: C,
5
2
48
2
4
2
benzene and filtered through a silica plug (3 cm) and the solvent
evaporated from the filtrate to yield [PhenTe] C as a pale yellow
58.15; H, 4.43. Despite multiple efforts analyses for carbon content
were consistently too low. For copies of the NMR spectra of
2
4
J
DOI: 10.1021/acs.inorgchem.9b02213
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
[
PyrTe] C , see Figure S17a−d. HRMS (APPI): calcd for
on the potential energy surface. To calculate phosphorescence
energies, the geometries of the lowest lying triplet states (T1)
were optimized by using UB3LYP (spin-unrestricted B3LYP)
with the same basis sets as specified above. The vertical
excitation energies of the first ten singlet and triplet states have
been predicted by TD-DFT computations using the B3LYP
functional as well as the cc-pVTZ(-PP) basis sets using the
2
4
+
C H B O Te [M + H] , 1019.1961; found, 1019.1943 (Δ1.8
ppm). Mp: 224 °C (dec.).
52
49
2
4
2
Synthesis of [BenzoTeBr ] C . CuBr (60.0 mg, 269 μmol) was
2
2
4
2
added to [BenzoTe] C (50.0 mg, 65.3 μmol) and 10 mL of a DMF/
H O mixture (4:1) was added, and the reaction mixture was stirred
for 12 h. The precipitate was allowed to settle and the supernatant
was decanted away. The remaining yellow solid was washed with
methanol (2 × 5 mL) and cold (−30 °C) dichloromethane (3 mL)
and dried in vacuo to yield a yellow solid of [BenzoTeBr ] C (12.2
mg, 14%). Crystals suitable for single-crystal X-ray diffraction
measurements were obtained by recrystallization from dichloro-
methane/methanol at room temperature. H NMR (699.8 MHz,
CDCl ): δ [ppm] = 7.85 (d, J = 8.4 Hz, 2H, ArH), 7.56 (ddd, J
2
4
2
respective B3LYP/cc-pVTZ(-PP) optimized gas-phase S
0
geometry. Phosphorescence energies have been calculated as
the difference of the energies at the UB3LYP-optimized T1
2
2 4
geometry and the B3LYP-optimized S geometry. As B3LYP
0
1
has known difficulties in correctly assigning the order of
3
3
29
3
HH
HH
excitations for pyrene and pyrene derivatives, TD-DFT
3
4
=
7.5 Hz, J = 6.6 Hz, J = 0.8 Hz, 2H, ArH), 7.52−7.50 (m, 4H,
HH
HH
calculations have also been performed with the CAM-B3LYP
functional using the cc-pVTZ(-PP) basis set for PhenTe,
ArH), 3.03−3.00 (m, 4H, CH ), 1.85−1.82 (m, 4H, CH ), 1.32 (s,
2
(
3
2
2
13
1
4H, CH ). C{ H} NMR (176.0 MHz, CDCl ): δ [ppm] = 149.5
3
3
PyrTe, [BenzoTe] C , [PhenTe] C , and [PyrTe] C (based
qC), 131.7 (CH), 131.3 (CH), 130.5 (CH), 130.2 (CH), 85.9 (OC),
2
4
2
4
2
4
1
1
1.5 (CH ), 28.4 (CH ), 24.9 (CH ). B NMR (128.3 MHz,
on the respective B3LYP optimized S
ground state geometry).
0
2
2
3
CDCl ): δ [ppm] = 31.7 (br). Anal. Calcd for C H B O Te Br
All computations have been carried out with the Gaussian16
software. The presented molecular orbitals (MOs) were
3
32 40
2
4
2
4
42
[
%]: C, 35.42; H, 3.72. Found: C, 34.32; H, 2.55. HRMS (MALDI):
+
calcd for C H B O Te Br [M − Br] , 1006.8742; found, 1006.8727
(
32
40
2
4
2
3
extracted from the Gaussian16 checkpoint-files and are
Δ1.5 ppm). Mp: 222 °C (decomp.).
43
visualized with VMD.
Attempted Polymerization of BrBenzoTe. A solution of ClPd-
In order to study the weak CH···π interaction in [BenzoTe-
Oc]·MeCN, the geometry was optimized using the B3LYP/cc-
pVTZ(-PP) level of theory and dispersion effects were
(
XPhos)(2-aminobiphenyl) (1.50 mg, 1.96 μmol) and THF (0.2 mL)
Br
was added to a solution of 5/6- BenzoTe (1:1 mixture, 50.0 mg,
9
7.9 μmol) and THF (0.8 mL). After 5 min, K PO (2.0 M solution
3 4
44
modeled using Grimme’s GD3BJ parameters. The wave
in H O, 0.15 mL, 290 μmol) was added, and the reaction mixture was
2
stirred at 50 °C overnight and then cooled to room temperature.
Water (10 mL) and dichloromethane (10 mL) were added and the
organic phase was separated, washed with water (2 × 10 mL) and
function files were used for topological analysis of the electron
density according to the Atoms-In-Molecules space-partition-
2
4
45
ing scheme using AIM2000, The Non-covalent interaction
46
dried over MgSO . After filtration the organic phase was dried in
4
(NCI) grids were computed with NCIplot. Bond paths are
displayed with AIM2000, and NCI figures are displayed with
VMD, respectively
vacuo. The yellow-green residue was washed with n-hexanes (3 × 10
mL) and dried in vacuo affording 3.1 mg of a crude mixture
45
43
containing oligomeric [BenzoTe] . Despite the multiple washing
n
Br
attempts, the protodeboronated side-product BenzoTeH remained
ASSOCIATED CONTENT
Supporting Information
in the crude mixture. (Figure S19a).
■
Br
1
BenzoTeH was prepared independently for comparison of the H
*
S
Br
NMR chemical shifts by reacting 5/6- BenzoTe (1:1 mixture, 33.2
mg, 65.0 μmol) with K CO (2.0 M solution in H O, 0.08 mL, 200
The Supporting Information is available free of charge on the
ACS Publications website at DOI: 10.1021/acs.inorg-
chem.9b02213.
2
3
2
μmol) in THF (4 mL) at 80 °C in a microwave reactor for 1 h. Water
(
10 mL) and dichloromethane (10 mL) were added and the organic
Full crystallographic, computational, and luminescence
measurement details, along with copies of NMR spectra
for all newly reported compounds (PDF)
phase was separated, washed with water (2 × 10 mL) and dried over
MgSO . After filtration the organic phase was dried in vacuo affording
1
4
Br
1
2.8 mg of crude 5/6- BenzoTe-H. H NMR (399.8 MHz, CDCl ):
3
δ [ppm] = 8.61 (s, 1H, ArH
), 8.55 (s, 2H, ArHBrBenzoTeH),
BrBenzoTeH
Atomic coordinates for all computed structures (XYZ)
4
4
8
.14 (d, J = 1.8 Hz, 1H, ArH
), 8.09 (d, J = 1.8 Hz,
HH
BrBenzoTeH
HH
3
0.6H, ArHpoly[BenzoTe]n), 7.86 (d, J = 8.3 Hz, 1H, ArHBrBenzoTeH),
Accession Codes
HH
.82 (d, 4J = 1.6 Hz, 0.7H, ArHpoly[BenzoTe]n), 7.81 (d, 4J = 2.1 Hz,
H, ArHBrBenzoTeH), 7.77 (d, 3JHH = 9.3 Hz, 0.6H, ArHpoly[BenzoTe]n),
CCDC 1922124−1922133 contain the supplementary crys-
tallographic data for this paper. These data can be obtained
free of charge via www.ccdc.cam.ac.uk/data_request/cif, or by
emailing data_request@ccdc.cam.ac.uk, or by contacting The
Cambridge Crystallographic Data Centre, 12 Union Road,
Cambridge CB2 1EZ, UK; fax: +44 1223 336033.
7
2
7
HH
HH
.54−7.34 (m, 27H, ArHpoly[BenzoTe]n+BrBenzoTeH).
COMPUTATIONAL METHODOLOGY
■
Geometry optimizations of the gas-phase structures have been
performed using density functional theory (DFT) with the
AUTHOR INFORMATION
Corresponding Authors
*(E.R.) E-mail: erivard@ualberta.ca.
*(G.H.) E-mail: ganghe@mail.xjtu.edu.cn.
■
3
8
B3LYP functional, and cc-pVTZ (for B, C, H, and, if
3
9
applicable, N) as well as cc-pVTZ-PP (for Te and, if
4
0
applicable, Br) basis sets; the cc-pVTZ-PP basis set uses an
effective core potential (ECP) accounting for 28 electrons
Te) and 10 electrons (Br), respectively. Initial molecular
ORCID
(
Emanuel Hupf: 0000-0003-0121-7554
Michael J. Ferguson: 0000-0002-5221-4401
Robert McDonald: 0000-0002-4065-6181
Toshiaki Murai: 0000-0003-4945-0996
Eric Rivard: 0000-0002-0360-0090
geometries were taken from the experimentally obtained X-ray
structures. For Oc-Te-Oc, PyrTe, BenzoTe, Benzo[a]PyrTe,
Dibenzo[a,e]PyrTe and Naphtho[2,3-a]PyrTe the starting
geometries were set up manually. The outlined basis sets as
well as the ECP for the Te and Br atoms were obtained from
4
1
the Basis Set Exchange Library. Subsequent frequency
Notes
analysis confirmed all obtained structures to be local minima
The authors declare no competing financial interest.
K
DOI: 10.1021/acs.inorgchem.9b02213
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
Xu, L.; Yu, H.; Boone, M. P.; de Souza, G. L. C.; McDonald, R.;
Ferguson, M. J.; He, G.; Brown, A.; Rivard, E. Aerobic Solid State Red
Phosphorescence from Benzobismole Monomers and Patternable
Self-Assembled Block Copolymers. Angew. Chem., Int. Ed. 2018, 57,
ACKNOWLEDGMENTS
■
This work was supported by NSERC of Canada (Discovery,
Accelerator, and CREATE grants to E.R.). E.H. thanks the
Deutsche Forschungsgemeinschaft (DFG) for a research
fellowship (HU 2512/1-1). Y.T. thanks the Japan Public−
Private Partnership Student Study Abroad Program-TOBI-
TATE! Young Ambassador Program (S171N137010001,
members from MEXT, JASSO, private sectors, and uni-
versities). The computational studies in this work were made
possible by the facilities of the Shared Hierarchical Academic
Computing Network (SHARCNET: www.sharcnet.ca), West-
Grid (www.westgrid.ca), and Compute/Calcul Canada (www.
computecanada.ca). G.H. thanks the Natural Science Founda-
tion of China (21704081, 21875180) and the Cyrus Chung
Ying Foundation for support. E.R. also acknowledges the
Alexander von Humboldt Foundation and the Japan Society
for the Promotion of Science (JSPS) for fellowships. We also
thank Mr. Samuel Baird for creating the TOC graphic.
1
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