Photochemical Structural Transformation of a Linear 1D Coordination Polymer Impacts the Electrical Conductivity

Article abstract of DOI:10.1021/acs.inorgchem.8b00833

A pair of 4-(1-naphthylvinyl)pyridine (4-nvp) ligands has been successfully aligned in head-to-tail fashion in a one-dimensional (1D) double chain ladder polymer [Cd(adc)(4-nvp)₂(H₂O)]_n (1; H₂adc = acetylenedicarboxylic acid) that undergoes a photochemical [2 + 2] cycloaddition reaction accompanied by single-crystal to single-crystal (SCSC) structural transformation from a 1D chain to a 2D layer structure. These structural changes have a significant impact on the conductivity and Schottky nature of the compound.

Full text of DOI:10.1021/acs.inorgchem.8b00833

Communication
pubs.acs.org/IC
Cite This: Inorg. Chem. XXXX, XXX, XXX−XXX
Photochemical Structural Transformation of a Linear 1D
Coordination Polymer Impacts the Electrical Conductivity
Basudeb Dutta,† Arka Dey,‡ Chittaranjan Sinha,§ Partha Pratim Ray,*,‡
and Mohammad Hedayetullah Mir*,†
†Department of Chemistry, Aliah University, New Town, Kolkata 700 156, India
‡Department of Physics, Jadavpur University, Jadavpur, Kolkata 700 032, India
§Department of Chemistry, Jadavpur University, Jadavpur, Kolkata 700 032, India
S
* Supporting Information
Schottky nature.24−26 MacGillivray et al. have demonstrated
the effect of photodimerization on the conductivity of a
metal−organic complex.29 However, there is no example on
how photodimerization affects the conductivity properties of
CP. Herein, we report an acetylenedicarboxylate based 1D CP
[Cd(adc)(4-nvp)2(H2O)]n (1; H2adc = acetylenedicarboxylic
acid), which undergoes photochemical [2 + 2] cycloaddition
accompanied by SCSC structural transformation from 1D
chain to 2D layer structure. Interestingly, this structural change
on photodimerization has an impact on the Schottky nature of
compound 1.
ABSTRACT: A pair of 4-(1-naphthylvinyl)pyridine (4-
nvp) ligands has been successfully aligned in head-to-tail
fashion in a one-dimensional (1D) double chain ladder
polymer [Cd(adc)(4-nvp)2(H2O)]n (1; H2adc = acetyle-
nedicarboxylic acid) that undergoes a photochemical [2 +
2] cycloaddition reaction accompanied by single-crystal to
single-crystal (SCSC) structural transformation from a 1D
chain to a 2D layer structure. These structural changes
have a significant impact on the conductivity and Schottky
nature of the compound.
The pale yellow needle-like crystals of 1 were grown in 60%
yield by slow diffusion of 4-nvp and H2adc in ethanol into a
solution of aqueous Cd(NO3)2·6H2O and Et3N in H2O/
MeOH (Scheme S1). Single crystal X-ray diffraction (SCXRD)
reveals that compound 1 crystallizes in the triclinic space group
ingle-crystal to single-crystal (SCSC) structural trans-
Sformation of coordination polymers (CPs) has attained a
great deal of interest in solid-state chemistry, because the final
products can be characterized unambiguously by single crystal
X-ray crystallography, which may be otherwise unattainable in
solution.1,2 Of these, structural transformation via photo-
chemical [2 + 2] cycloaddition attains a special interest.3−5
Ditopic spacer 1,2-bis(4′-pyridyl)ethylene (bpe) and mono-
topic terminal ligand 4-styrylpyridine (4-spy) have been used
in CPs for studying topochemical structural transformation.3−8
Recently, monotopic 4-(1-naphthylvinyl)pyridine (4-nvp) has
also been used for the same purpose.9 However, conversion of
CP from one-dimensional (1D) to two-dimensional (2D)
structure by photodimerization is still rare in the literature.
One of the strategies of synthesizing 1D CP is to employ
acetylenedicarboxylate (¯O2CCCCO2¯), which acts as a
dianionic linear connector in the fabrication of CPs.10,11
In the past few decades, successful attempts have been made
for the topochemical structural transformation via photo-
chemical [2 + 2] cycloaddition.3−5,12−16 However, despite
having few reports in the literature, the effects of photo-
dimerization on physical properties of CPs have remained
largely unexplored.17−22 Additionally, CPs have currently
emerged as an important class of solid-state materials and
have been characterized with conductive properties for
application in Schottky diodes as well as a photosensing
devices.23−26 It is important to mention that the electronic
properties of the CPs depend on a judicious choice of organic
linkers as well as metal ions. CPs prepared from d10 metal ions
(Zn2+, Cd2+ etc.) with conjugated carboxylate linkers are found
to show semiconducting properties27,28 and can behave in a
̅
P1 with Z = 2. Each Cd(II) center has a distorted octahedral
geometry, being coordinated to two 4-nvp ligands disposed in
trans fashion along with an adc ligand in a monodentate
fashion and an aqua ligand. Two such Cd(II) centers are
bridged by two bridging adc ligands to form a dimeric unit
which propagates along the a axis to generate a 1D double
chain ladder polymer (Figure 1) resembling with the structure
reported by Lang group.30 The Cd···Cd distance in the ladder
is 4.81 Å. The axial 4-nvp ligands are projected on both sides of
dimeric units of the ladder, resulting in the formation of empty
spaces between 4-nvp ligands of the chain. This facilitates the
1D ladders to be mutually interdigitated to form a 2D layer
structure (Figure S2).
Interestingly, 4-nvp ligand of one ladder is exactly aligned
parallel in a head-to-tail fashion to the 4-nvp ligand of the
adjacent ladder (Figure 1). There are π···π stacking
interactions between pyridine and naphthalene groups with a
centroid−centroid distance of 3.60 Å. The bond distance
between the center of the adjacent CC bonds is 3.67 Å,
which indicates the possibility of photochemical [2 + 2]
cycloaddition. However, of a pair of 4-nvp ligands of a dimeric
unit, only one ligand undergoes alignment with that of the
adjacent ladder, indicating 50% of 4-nvp ligands have the
possibility of photodimerization. Furthermore, the 2D layers
undergo strong intermolecular hydrogen bonding interactions
Received: March 28, 2018
© XXXX American Chemical Society
A
DOI: 10.1021/acs.inorgchem.8b00833
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Communication
Figure 1. A perspective view of alignment of 4-nvp ligands between
adjacent chains in 1. Distances are in Å. Only selected atoms are
shown for clarity.
Figure 2. A perspective view of two adjacent chains in 1 after UV
irradiation. Only selected atoms are shown for clarity.
between the aqua ligand and noncoordinated oxygen atom of
adc with an O···O separation of 2.76−2.90 Å to form a three-
dimensional (3D) supramolecular aggregate (Figure S3).
The alignment of CC bonds between the pair of 4-nvp
ligands follows Schmidt’s criteria (<4.2 Å) for photochemical
cycloaddition, which prompted us to conduct photoirradiation
of 1 using UV light.31,32 The single crystals of 1 were subjected
to UV irradiation (λ = 350 nm) using a mercury lamp for 30
1
min. The H NMR spectrum of compound 1 in d6-DMSO
shows the appearance of the δ 5.17 cyclobutane proton of 1,3-
bis(4′-pyridyl)-2,4-bis(naphthyl)cyclobutane (rctt-4-pncb),
which is evident for the photodimerization as reported earlier.9
Moreover, the transparency and shape of the crystals remains
intact after 30 min of UV irradiation, only the color of the
dimerized product becomes intense. These results propelled us
to investigate SCSC transformation of compound 1.
The SCXRD of the irradiated product [Cd(adc)(4-nvp)-
(rctt-4-pncb)1/2(H2O)]n, (1′) reveals a quantitative photo-
dimerization of aligned 4-nvp ligands accompanied by SCSC
structural transformation from a 1D ladder to a 2D layer
structure (Figure 2). As a result, the distance between two
Cd(II) centers attached to aligned 4-nvp ligands of adjacent
ladders decreases from 14.80 Å in 1 to 14.44 Å in 1′. The π···π
interactions between pyridine and naphthalene groups also
decrease from 3.60 Å in 1 to 3.41 Å in 1′.
Figure 3. (A) Nyquist impedance plots. (B) Bode plots. (C)
Dependency of AC conductivity on frequency. (D) Capacitance vs
frequency graph of 1 and 1′, respectively.
(Figure 3B), which represents the characteristic peak position
and frequency related to the inverse of the electron lifetime
(τn) of the compounds.27 From this study it is obvious that the
characteristic frequency is related to the electron lifetime and
the longer electron lifetime corresponds to smaller frequency.
We have studied the frequency (f) dependency of AC
conductivity (Figure 3C), which gives an idea on the interior
of the semiconductor, a region of relatively low conductivity
when the conduction process is electrode-limited.34 With the
increase in frequency, the conductivity decreases when it
depends on free carriers.33 The relative dielectric constant was
measured on disc shaped pellet of as-synthesized 1 and 1′
(diameter 6.12 mm and thickness 1.4 mm) from the frequency
(f) vs capacitance (C) plot at constant bias potential (Figure
3D). At room temperature, the frequency dependent
capacitance of 1 and 1′ decreases with increase in frequency
and becomes saturated at higher frequency. At the saturation
level, the relative permittivity of the compounds was calculated.
All the measured parameters are listed in Table S4.
In this work, the direct optical band gap (Eg) of 1 and 1′
were evaluated as 3.33 and 3.21 eV respectively, using Tauc’s
plot33 (Figure S5), described in the Supporting Information.
The optical band gaps essentially match well with the ΔE
(HOMO−LUMO gap) values obtained from DFT computa-
tions (Figure S6). The obtained band gaps falling within the
semiconductor limit motivated us to check further the inherent
electrical conductivity of the compounds in terms of dielectric
study from impedance spectroscopy (IS).
Figure 3A signifies the complex plane impedance plots, i.e.,
the Nyquist plots for 1 and 1′, which reveal the prominent arc
of a semicircle. From the radius of the semicircle, the charge
transfer resistance Rct (DC resistance) of the compounds was
calculated. Here, 1′ possesses a small semicircle arc which
primarily signifies small charge transfer resistance (Rct) and
better conducting nature compared to 1. To extend this study,
we have plotted Bode phase diagram of the compounds
The impedance analysis further impelled us to look into the
inherent electrical properties of 1 and 1′. Hence, the electrical
B
DOI: 10.1021/acs.inorgchem.8b00833
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Communication
characterization was accomplished by fabricating an ITO/(1 or
1′)/Al sandwich structured metal (Al)−semiconductor (1 or
1′) (MS) junction, and the representative I−V characteristics
are displayed in Figure 4. The conductivities of 1 and 1′ were
measured as 1.83 × 10−3 Sm−1 and 3.91 × 10−3 Sm−1,
respectively, signifying a recognizable enhancement of 1′ as
compared to 1.
Figure 5. (A) log I vs logV curve. (B) I vs V2 curve for 1 and 1′.
charge transport properties have been improved for 1′. All the
diode parameters also demonstrate the enhanced charge
transfer kinetics for 1′ as compared to 1.
In summary, we have synthesized a linear 1D coordination
polymer which undergoes photochemical [2 + 2] cycloaddition
accompanied by SCSC topochemical structural tranformation
from a 1D double chain to a 2D layer structure. This structural
transformation leads to a decrease in distance between the
adjacent chains as well as π···π stacking interactions resulting in
an increase in conductivity. To the best of our knowledge, this
appears to be a rare example, where [2 + 2] cycloaddition has
an impact on electrical conductivity and the Schottky nature of
the CP. Therefore, this kind of material can be used as a
promising candidate for future device application.
Figure 4. I−V characteristics curve for ITO/compound 1/Al and
ITO/compound 1′/Al.
Evidently, the representative I−V characteristics of the
compounds exhibited a nonlinear rectifying nature, which is
the signature of a Schottky barrier diode (SBD).35,36 Hence,
the rectification ratios (Ion/Ioff) were calculated as 25.25 and
33.12, respectively, for 1 and 1′ at 2 V. The values of ideality
factors are obtained as 2.89 and 1.92 for 1 and 1′, respectively.
All the measured parameters, e.g., potential height (⌀B),
ideality factor (η), and series resistance (RS) for 1′, show better
performance compared to 1 (Table S5). It is important to
mention that the value of the ideality factor of 1′ approached
closer to 1, indicating a more ideal device. This is an indication
of less interfacial charge recombination and better homoge-
neity of Schottky junctions.37 Additionally, the higher
rectification ratio for 1′ is attributed to the lower barrier
height. The lowered value of series resistance of 1′ is attributed
to the large increase of charge carriers. Here, the decrease in
distance between the adjacent chains together with shrinkage
of π···π stacking interactions between pyridine and naph-
thalene groups results in an increase in conductivty after
photodimerization.23 All these observations portrayed the
dimerized product 1′ as a good contender in the field of
electronic devices.
To get insight into the charge transport phenomena, the I−
V curves have been studied in detail. The characteristic I−V
curves revealed the presence of two different regions marked as
region I and region II (Figure 5A). In region I (slope is ∼1),
current follows with relation I ∝ V, which refers to the Ohmic
regime. In region II (slope is ∼2), current is proportional to V2
(Figure 5A), corresponding to the characteristic trap free space
charge limited current (SCLC) regime.33,37
Using this model, the mobility has been estimated for 1 and
1′ as 1.92 × 10−9 and 3.93 × 10−9 m2 V−1 s−1, respectively,
from the higher voltage region of the I vs V2 plot by Mott−
Gurney law (Figure 5B).33,37 The effective carrier mobility,
transit time, carrier concentration, and diffusion length have
been depicted in Table S6, which clearly indicates that the
ASSOCIATED CONTENT
■
S
* Supporting Information
The Supporting Information is available free of charge on the
ACS Publications website at DOI: 10.1021/acs.inorg-
chem.8b00833.
Details of the synthesis, elemental analysis, device
fabrication, Figures S1−S7, Tables S1−S7, PXRD,
TGA, and NMR (PDF)
Accession Codes
CCDC 1831710−1831711 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.
AUTHOR INFORMATION
■
Corresponding Authors
*E-mail: partha@phys.jdvu.ac.in.
*E-mail: chmmir@gmail.com.
ORCID
Chittaranjan Sinha: 0000-0002-4537-0609
Partha Pratim Ray: 0000-0003-4616-2577
Mohammad Hedayetullah Mir: 0000-0002-2765-6830
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
This work was supported by SERB, India (Grant No. SB/FT/
CS-185/2012, dated 30/07/2014). B.D. thanks the DST for
INSPIRE fellowship.
C
DOI: 10.1021/acs.inorgchem.8b00833
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Communication
Based on the Photoinduced Single-Crystal-to-Single-Crystal Rever-
sible Transformation of a syn-[2.2]Metacyclophane. Inorg. Chem.
2018, 57, 849−856.
REFERENCES
■
(1) Kole, G. K.; Vittal, J. J. Crystal Engineering of Top-
ochemicalSolid State Reactions. Chem. Soc. Rev. 2013, 42, 1755−
1775.
(2) Chaudhary, A.; Mohammad, A.; Mobin, S. M. Recent Advances
in Single-Crystal-to-Single-Crystal Transformation at the Discrete
Molecular Level. Cryst. Growth Des. 2017, 17, 2893−2910.
(3) Nagarathinam, M.; Peedikakkal, A. M. P.; Vittal, J. J. Stacking of
DoubleBonds For Photochemical [2 + 2] Cycloaddition Reactions in
the Solid State. Chem. Commun. 2008, 5277−5288.
(4) Medishetty, R.; Park, I.-H.; Lee, S. S.; Vittal, J. J. Solid-State
Polymerisation via [2 + 2] Cycloaddition Reaction Involving
Coordination Polymers. Chem. Commun. 2016, 52, 3989−4001.
(5) Mir, M. H.; Koh, L. L.; Tan, G. K.; Vittal, J. J. Single-Crystal to
Single-Crystal Photochemical Structural Transformations of Inter-
penetrated 3 D Coordination Polymers by [2 + 2] Cycloaddition
Reactions. Angew. Chem., Int. Ed. 2010, 49, 390−393.
(6) Medishetty, R.; Koh, L. L.; Kole, G. K.; Vittal, J. J. Vittal. Solid
State Structural Transformation from 2D-Interdigitated Layer to 3D-
Interpenetrated Structure. Angew. Chem., Int. Ed. 2011, 50, 10949−
10952.
(7) Medishetty, R.; Yap, T. T. S.; Koh, L. L.; Vittal, J. J. Thermally
Reversible Single-Crystal to Single-Crystal Transformation of
Mononuclear to DinuclearZn(II) Complexes by [2 + 2] Cyclo-
addition Reaction. Chem. Commun. 2013, 49, 9567−9569.
(8) Medishetty, R.; Tandiana, R.; Koh, L. L.; Vittal, J. J. Assembly of
3D Coordination Polymers from 2D Sheets by [2 + 2] Cycloaddition
Reaction. Chem. - Eur. J. 2014, 20, 1231−1236.
(9) Hu, F.-L.; Wang, S.-L.; Abrahams, B. F.; Lang, J.-P. Observance
of a large conformational change associated with the rotation of the
naphthyl groups during the photodimerization of crisscross aligned
CC bonds within a 2D coordination polymer. CrystEngComm
2015, 17, 4903−4911.
(10) Turner, D. R.; Strachan-Hatton, J.; Batten, S. R. Steric Control
of 4-connected Network Topology in Hydrogen Bonded Coordina-
tion Polymers. CrystEngComm 2008, 10, 34−38.
(11) Ahmed, F.; Datta, J.; Dutta, B.; Naskar, K.; Sinha, C.; Alam, S.
M.; Kundu, S.; Ray, P. P.; Mir, M. H. Cation Dependent Charge
Transport in Linear DicarboxylateBased Isotypical 1D Coordination
Polymers. RSC Adv. 2017, 7, 10369−10375.
(12) MacGillivray, L. R.; Papaefstathiou, G. S.; Friscic, T.; Hamilton,
T. D.; Bucar, D.-K.; Chu, Q.; Varshney, D. B.; Georgiev, I. G.
Supramolecular control of reactivity in the solid state: from templates
to ladderanes to metal−organic frameworks. Acc. Chem. Res. 2008, 41,
280−291.
(13) MacGillivray, L. R.; Papaefstathiou, G. S.; Friscic, T.; Varshney,
D. B.; Hamilton, T. D. Template-Controlled Synthesis in the Solid-
State. Top. Curr. Chem. 2005, 248, 201−221.
(14) Georgiev, I. G.; MacGillivray, L. R. Metal-mediated reactivity in
the organic solid state: from self-assembled complexes to metal−
organic frameworks. Chem. Soc. Rev. 2007, 36, 1239−1248.
(15) Nagarathinam, M.; Vittal, J. J. A Rational Approach to
Crosslinking of Coordination Polymers Using the Photochemical [2 +
2] Cycloaddition Reaction. Macromol. Rapid Commun. 2006, 27,
1091−1099.
(16) Eubank, J. F.; Kravtsov, V. C.; Eddaoudi, M. Synthesis of
Organic Photodimeric Cage Molecules Based on Cycloaddition via
Metal−Ligand Directed Assembly. J. Am. Chem. Soc. 2007, 129,
5820−5821.
(20) Shi, Y.-X.; Li, W.-X.; Chen, H.-H.; Young, D. J.; Zhang, W.-H.;
Lang, J.-P. A crystalline zinc(II) complex showing hollow hexagonal
tubular morphology evolution, selective dye absorption and unique
response to UV irradiation. Chem. Commun. 2017, 53, 5515−5518.
(21) Hu, F.-L.; Wang, H.-F.; Guo, D.; Zhang, H.; Lang, J.-P.; Beves,
J. E. Controlled formation of chiral networks and their reversible
chiroptical switching behaviour by UV/microwave irradiation. Chem.
Commun. 2016, 52, 7990−7993.
(22) Liu, D.; Ren, Z.-G.; Li, H.-X.; Lang, J.-P.; Li, N.-Y.; Abrahams,
B. F. Single-Crystal-to-Single-Crystal Transformations of Two Three-
Dimensional Coordination Polymers through Regioselective [2 + 2]
Photodimerization Reactions. Angew. Chem., Int. Ed. 2010, 49, 4767−
4770.
̆
(23) Sun, L.; Campbell, M. G.; Dinca, M. Electrically Conductive
Porous Metal−Organic Frameworks. Angew. Chem., Int. Ed. 2016, 55,
3566−3579.
(24) Bhattacharya, B.; Layek, A.; Mehboob Alam, M.; Maity, D. K.;
Chakrabarti, S.; Ray, P. P.; Ghoshal, D. Cd(II) Based Metal−Organic
Framework Behaving as a Schottky Barrier Diode. Chem. Commun.
2014, 50, 7858−7861.
(25) Roy, S.; Dey, A.; Ray, P. P.; Ortega-Castro, J.; Frontera, A.;
Chattopadhyay, S. Application of a Novel 2D Cadmium(II)-MOF in
the Formation of a Photo-Switch with a Substantial on−off ratio.
Chem. Commun. 2015, 51, 12974−12976.
(26) Maity, D. K.; Dey, A.; Ghosh, S.; Halder, A.; Ray, P. P.;
Ghoshal, G. Set of Multifunctional Azo Functionalized Semi-
conducting Cd(II)-MOFs Showing Photoswitching Property and
Selective CO2 Adsorption. Inorg. Chem. 2018, 57, 251−263.
(27) Naskar, K.; Dey, A.; Dutta, B.; Ahmed, F.; Sen, C.; Mir, M. H.;
Roy, P. P.; Sinha, C. Intercatenated Coordination Polymers (ICPs) of
CarboxylatoBridged Zn (II)-Isoniazid and Their Electrical Con-
ductivity. Cryst. Growth Des. 2017, 17, 3267−3276.
(28) Li, W.-J.; Liu, J.; Sun, Z.-H.; Liu, T.-F.; Lu, J.; Gao, S.-Y.; He,
̈
C.; Cao, R.; Luo, J.-H. Integration of Metal-Organic Frameworks into
an Electrochemical Dielectric Thin Film for Electronic Applications.
Nat. Commun. 2016, 7, 11830−11837.
(29) Hutchins, K. M.; Rupasinghe, T. P.; Ditzler, L. R.; Swenson, D.
C.; Sander, J. R. G.; Baltrusaitis, J.; Tivanski, A. V.; MacGillivray, L. R.
Nanocrystals of a Metal−Organic Complex Exhibit Remarkably High
Conductivity that Increases in a Single-Crystal-to-Single-Crystal
Transformation. J. Am. Chem. Soc. 2014, 136, 6778−6781.
(30) Liu, D.; Lang, J.-P.; Abrahams, B. F. Stepwise ligand
transformations through [2 + 2] photodimerization and hydrothermal
in situ oxidation reactions. Chem. Commun. 2013, 49, 2682−2684.
(31) Schmidt, G. M. J. Photodimerization in the solid state. Pure
Appl. Chem. 1971, 27, 647.
̌
̌
́
̌
̌
́
(32) Wegner, G. Solid-State Polymerization Mechanisms. Pure Appl.
Chem. 1977, 49, 443.
(33) Dey, A.; Middya, S.; Jana, R.; Das, M.; Datta, J.; Layek, A.; Ray,
P. P. Light Induced Charge Transport Property Analysis of
Nanostructured ZnS Based SchottkyDiode. J. Mater. Sci.: Mater.
Electron. 2016, 27, 6325−6335.
(34) Gould, R. D.; Hassan, A. K. Ac Electrical Properties of
Thermally Evaporated Thin Films of Copper Phthalocyanine. Thin
Solid Films 1993, 223, 334−340.
(35) Rhoderick, E. H. Metal Semiconductors Contacts; Oxford
University Press: Oxford, 1978.
(36) Dey, A.; Layek, A.; Roychowdhury, A.; Das, M.; Datta, J.;
Middya, S.; Das, D.; Ray, P. P. Investigation of Charge Transport
Properties in Less Defective Nanostructured ZnOBased Schottky-
Diode. RSC Adv. 2015, 5, 36560−36567.
(37) Blom, P. W. M.; de Jong, M. J. M.; van Munster, M. G. Electric-
Field and Temperature Dependence of the Hole Mobility in Poly (p-
phenylenevinylene). Phys. Rev. B: Condens. Matter Mater. Phys. 1997,
55, R656−R659.
(17) Sato, H.; Matsuda, R.; Mir, M. H.; Kitagawa, S. Photochemical
Cycloaddition on The Pore Surface of a Porous Coordination
Polymer Impacts the Sorption Behavior. Chem. Commun. 2012, 48,
7919−7921.
(18) Li, N.-Y.; Liu, D.; Abrahams, B. F.; Lang, J.-P. Covalent
switching, involving divinylbenzene ligands within 3D coordination
polymers, indicated by changes in fluorescence. Chem. Commun.
2018, 54, 5831−5834.
(19) Li, N.-Y.; Liu, D.; Ren, Z.-G.; Lollar, C.; Lang, J.-P.; Zhou, H.-
C. Controllable Fluorescence Switching of a Coordination Chain
D
DOI: 10.1021/acs.inorgchem.8b00833
Inorg. Chem. XXXX, XXX, XXX−XXX