The Structure and Characterization of 3,4,5-Triiodo-2-Methylthiophene: An Unexpected Iodination Product of 2-Methylthiophene

Article abstract of DOI:10.1007/s10870-019-00770-z

Abstract: We report the structure and characterization of 3,4,5-triiodo-2-methylthiophene, obtained as an unexpected, unreported, and significant side product from the iodination of 2-methylthiophene using iodine and iodic acid. Identity of this unexpected product was confirmed by X-ray crystallography and ¹H and ¹³C NMR. The compound crystallizes in the P2₁/c space group with unit cell parameters a = 16.4183(10) ?, b = 4.1971(3) ?, c = 14.3888(9) ?, β = 111.4442(14), Z = 4, and D_calc = 3.425?g?cm^?3. Analysis of residual electron density maps indicated the presence of crystallographic disorder between the 2-methyl and 5-iodo positions leading to a model of two distinct molecules of 3,4,5-triiodo-2-methylthiophene where the atoms of these two groups were exchanged. Non-covalent iodine–iodine and sulfur–iodine interactions are observed. Graphical Abstract: Three products, two of which are constitutional isomers, are possible when installing multiple iodine atoms on 2-methylthiophene; X-ray structural analysis and spectral characterization show that the 4,5-diiodo isomer is not formed and that the 3,4,5-triiodo isomer is unexpectedly obtained. Halogen and chalcogen bonding are clearly observed. [Figure not available: see fulltext.].

Full text of DOI:10.1007/s10870-019-00770-z

Journal of Chemical Crystallography
https://doi.org/10.1007/s10870-019-00770-z
BRIEF COMMUNICATION
The Structure and Characterization of 3,4,5-Triiodo-2-
Methylthiophene: An Unexpected Iodination Product
of 2-Methylthiophene
Dinesh G. Patel1 · Eric D. Sylvester · Nicholas R. LeValley · Travis B. Mitchell · Jason B. Benedict
2
1
2
2
Received: 16 August 2018 / Accepted: 17 January 2019
©
Springer Science+Business Media, LLC, part of Springer Nature 2019
Abstract
We report the structure and characterization of 3,4,5-triiodo-2-methylthiophene, obtained as an unexpected, unreported,
and significant side product from the iodination of 2-methylthiophene using iodine and iodic acid. Identity of this unex-
1
13
pected product was confirmed by X-ray crystallography and H and C NMR. The compound crystallizes in the P2 /c
1
space group with unit cell parameters a=16.4183(10) Å, b=4.1971(3) Å, c=14.3888(9) Å, β=111.4442(14), Z=4, and
−
3
D
=3.425 g cm . Analysis of residual electron density maps indicated the presence of crystallographic disorder between
calc
the 2-methyl and 5-iodo positions leading to a model of two distinct molecules of 3,4,5-triiodo-2-methylthiophene where
the atoms of these two groups were exchanged. Non-covalent iodine–iodine and sulfur–iodine interactions are observed.
Graphical Abstract
Three products, two of which are constitutional isomers, are possible when installing multiple iodine atoms on 2-methylth-
iophene; X-ray structural analysis and spectral characterization show that the 4,5-diiodo isomer is not formed and that the
3
,4,5-triiodo isomer is unexpectedly obtained. Halogen and chalcogen bonding are clearly observed.
Keywords Iodination reaction · Thiophene · Iodothiophene · Halogen bonding · Sigma-hole · Chalcogen bonding
Introduction
Electronic supplementary material The online version of this
article (https://doi.org/10.1007/s10870-019-00770-z) contains
Iodinated aromatic compounds are valuable synthetic inter-
supplementary material, which is available to authorized users.
mediates with reactivity higher than that of the correspond-
ing brominated and chlorinated aryl species, specifically in
*
Dinesh G. Patel
dgp15@psu.edu
metalation reactions and metal catalyzed coupling reactions
[
1, 2]. Typically, however, iodinated intermediates are more
Extended author information available on the last page of the article
Vol.:(0
1
123456789)
3

Journal of Chemical Crystallography
Scheme 1 The iodination of 1
can give a pair of diiodinated
regioisomers 2 and 3. A triiodi-
nated side product, 4, however,
is unexpectedly observed while
compound 3 is not observed
expensive than their brominated and chlorinated analogues.1
In some cases, the desired iodine compounds are not com-
mercially available [3]. Consequently, research aimed at
obtaining aromatic iodides has received much attention.
Relatively mild iodination methods using iodic acid in
conjunction with iodine or potassium iodide have been
employed with thiophene and thiophene derivatives [4–6]
in order to iodinate the less reactive three and four positions
needed for the synthesis of organic materials [7–10] and in
particular diarylethene photochromes [11–16]. Other elec-
tron rich substrates are also employed [4–6]. The attempt
at diiodination of 2-methylthiophene (1), as illustrated in
Scheme 1, presents a method for acquisition of the highly
desirable 3,5-diiodo-2-methylthiophene (2), expected to
be more reactive than the bromine analogue [17, 18]. The
constitutional isomer 4,5-diiodo-2-methlthiophene (3) has
been posited as another diiodinated product [4], but it was
not observed in our hands. Here we report the synthesis and
characterization of 3,4,5-triiodo-2-methylthiophene (4), an
unexpected byproduct of the diiodination of 2-methylthio-
phene. Crystallographic data shows the presence of halogen
and chalcogen bonding.
General Synthetic Procedures
Small-Scale Synthesis of 3,5-Diiodo-2-Methylthiophene (2)
and 3,4,5-Triiodo-2-Methyl Thiophene (4)
This procedure is identical to that reported by Sevez and
Pozzo [4]. To a 25 mL round bottom flask with reflux con-
denser was added 2-methylthiophene (0.500 g, 5.09 mmol),
acetic acid (3.75 mL), chloroform (3.75 mL), and iodine
(1.290 g, 5.09 mmol). With stirring, iodic acid (0.448 g,
2.55 mmol) previously dissolved in water (1.25 mL) was
added in portions over 5 min and the reaction was refluxed,
under nitrogen, at 80 °C for 24 h. After cooling to room
temperature, the reaction was diluted with hexane (30 mL).
The hexane phase was collected and the aqueous phase
was diluted with water (30 mL) and extracted with hexane
(2 × 30 mL). The combined hexane phases were washed
with water (30 mL), saturated aqueous sodium bicarbonate
(1×30 mL), 10 wt% aqueous sodium thiosulfate (30 mL),
and finally brine (30 mL). After drying over MgSO , filtra-
4
tion, and removal of solvent, a clear, brown oil was obtained.
1
By H NMR, the product yield was quantitative and two
products, based on methyl peaks, were present. The products
were adsorbed onto silica and separated by column chroma-
tography on silica eluting with hexane. The NMR spectra
obtained for compound 2 were consistent the literature report
as was the approximate yield [4]. White, needle-like X-ray
Materials and Experimental Details
All chemicals were obtained commercially and used as
1
13
received. H and C NMR spectra were acquired using a
Varian Inova NMR spectrometer operating at 400 MHz for
proton NMR and 100 MHz for carbon NMR. All spectra are
referenced to the residual solvent peak of chloroform-d at
quality crystals of 4 were obtained by slow evaporation of
1
hexane. For compound 4: H NMR (500 MHz, CDCl ) δ
3
13
2.55 (s, 3H); C NMR (125 MHz, CDCl ) δ 146.36, 106.59,
3
92.43, 78.23, 20.70.
7
.26 ppm. Reagents were combined in air and the reaction
was refluxed under a nitrogen atmosphere. Silica gel used
for chromatography was 70–230 mesh. Melting points were
obtained using a ThermoFisher Scientific IA9000 series
digital melting point apparatus and are uncorrected.
Large-Scale Synthesis of 3,5-Diiodo-2-Methylthiophene (2)
and 3,4,5-Triiodo-2-Methyl Thiophene (4)
Larger scale reactions (one order of magnitude greater) can
be run with product mixtures and spectral data identical to
that obtained from the small scale reaction. Running a larger
scale reaction presents the problem of separating compounds
2
and 4, which have similar R values when chromatograph-
f
ing on silica eluting with hexanes.
1
A price comparison can be found in Table S3.
1
3

Journal of Chemical Crystallography
Table 1 Summary of X-ray crystallographic data for 3,4,5,-triiodo-
exchanged leading to two distinct molecules of 4. The posi-
tions of the disordered groups were freely refined. The
occupancies of the disordered methyl and iodo groups were
constrained to be equivalent in each of the distinct molecules
with the additional constraint that the sum of the occupan-
cies for both distinct molecules must sum to 1.0. Ultimately,
the occupancies for the two disordered parts was determined
to be approximately 0.55 and 0.45. A summary of the crys-
tallographic data and details of the structure refinements are
listed in Table 1.
2
-methylthiophene (4)
CCDC no.
Empirical formula
Formula weight (g mol−1)
Temperature (K)
Wavelength (A)
Crystal system
Space group
Unit cell dimensions
a, Å
C H I S
5 3 3
475.83
90
0.71073
Monoclinic
P2 /c
1
16.4183(10)
4.1971(3)
14.3888(9)
111.4442(14)
922.88(10)
4
b, Å
c, Å
Results and Discussion
β, °
Volume (Å )
When the reaction illustrated in Scheme 1 is examined
by TLC (polyester backed silica stationary phase, hexane
3
Z
mobile phase), two spots of similar R are clearly observed.
f
Dcalc (g cm−3
)
3.425
10.307
1
However, the H NMR spectrum of the crude reaction
−
1
µ(MoK ) mm
α
(
Fig. 1) does not match the expected pattern if those spots
F(000)
832.0
were due to a mixture of compounds 2 and 3; were this the
case, two singlets should appear in the aromatic region. Only
one singlet is observed at 7.08 ppm, which is consistent with
the spectrum reported by Sevez and Pozzo [4] for compound
2
θ range (°)
5.332–62.018
− 23≤h≤23
Index ranges
−
−
5≤k≤5
20≤l≤19
2
. However, two prominent singlets are observed in the ali-
Reflections collected/unique (Rint)
18,676
2760/0/103
1.092
phatic region at 2.55 ppm and 2.42 ppm with a ratio of 1:4.6,
respectively. The peak at 2.42 ppm correlates with that of the
methyl peak expected from compound 2 when integration is
taken into account and according to the work by Sevez and
Pozzo. However, the source for the peak at 2.55 ppm could
Data/parameters
Goodness-of-fit on F2
Refinement method
Final R indices [I>2σ(l)]
R indices (all data)
Least-squares minimization
R =0.0188, wR =0.0438
1
2
R =0.0203, wR =0.0448
1
2
1
3
not be immediately identified. While the H NMR spectra of
Largest diff. peak and hole (e/Å )
1.23/− 1.20
various iodinated thiophenes has previously been reported,
these spectra were run in carbon tetrachloride using a low
field instrument in contrast to the 400 MHz instrument and
chloroform-d solvent used in these experiments [21].
X‑ray Crystallography
A single crystal of 4 was mounted on a glass fiber using
Paratone oil under atmospheric conditions. X-ray diffrac-
tion data was collected on a Bruker SMART APEX2 CCD
diffractometer installed on a rotating anode source (MoKα
radiation, λ = 0.71073 Å), and equipped with an Oxford
Cryosystems (Cryostream700) nitrogen gas-flow apparatus.
The data were collected by the rotation method with a 0.5°
frame-width (ω scan). Three sets of data (360 frames in each
set) were collected, nominally covering complete reciprocal
space. The structure was solved in the Olex2 [19] crystal-
lography program using the XT structure solution program
Fortuitously, a crystalline solid forms from the initially
obtained viscous oil. While the obtained solid was impure,
dissolution of the crude mixture and adsorption on silica fol-
lowed by chromatography on silica eluting with 100% hex-
anes allowed isolation this compound, which we observed
had limited solubility in hexane and crystallized slowly as
fractions were collected. The compound has a melting point
of 97–98 °C, close to the reported melting point of approxi-
mately 100–101 °C reported separately by Steinkopf and
Takahashi for 3,4,5,-triiodo-2-methylthiophene [21, 22] and
identical to that reported by Gronowitz [23]. The obtained
crystals were of X-ray quality and subjected to X-ray diffrac-
tion analysis, which showed that the anomalous product was
indeed triiodinated compound 4 (Fig. 2). Compound 4 has
[
19] using the Intrinsic Phasing method and refined using
the SHELXL refinement package [20] using least-squares
minimization. Non-hydrogen atoms were refined anisotropi-
cally and hydrogen atoms were placed at idealized positions
and then allowed to be freely refined. Analysis of residual
electron density maps from initial refinements indicated the
presence of crystallographic disorder between the 2-methyl
and 5-iodo positions. The atoms of these two groups were
1
no aromatic protons and the H NMR spectrum correlates
with the crystal structure obtained from pure 4.
Compound 4 crystallizes in a herringbone type struc-
ture and exhibits crystallographic disorder between the
2-methyl and 5-iodo positions. This leads to a model of two
1
3

Journal of Chemical Crystallography
1
Fig. 1 Crude H NMR of the iodination reaction of 2-methylthiophene with proton peaks, integration, and chemical shifts labeled. The residual
solvent peak is used as an internal standard
distinct molecules of 4 where the atoms of the 5-iodo and the
the van der Waals distance of 3.78 Å for S–I. The C4–I2–S
bond angle of 171.37° suggests that the sulfur lone pair are
interacting with the σ-hole of I2.
2
-methyl groups are exchanged. When measuring the bond
lengths of C(3)–I(1) and C(4)–I(2), distances of 2.085(12)
Å and 2.081(2) Å, respectively, are observed. These lengths
are identical to those reported by Allen and coworkers for
The tetramers also exhibit lateral short I1–I1 contacts of
3.771 Å (Fig. 4). These interactions form a zig-zag chain
that propagates parallel to (010). Similar to above, the σ-hole
of I1 appears to be interacting with the lone pairs on the
neighboring I1 atoms.
C –I bonds when standard deviations are taken into account
ar
[
24]. The bonds C(2)–I(3A) and C(5)–I(3) are shorter at
2
.012(2) Å and 2.026(2) Å, respectively, likely due to the
effects of non-covalent interaction between sulfur atoms and
neighboring iodine atoms.
When examining short contacts and the resultant bond
angles, evidence supporting halogen bonding [25] and chal-
cogen bonding [26] is observed. The first set of halogen and
chalcogen bonds forms a tetramer of 4 (Fig. 3). At 3.673
and 3.826 Å, the non-covalent I2–I3 and I3–I3 interactions,
respectively, are shorter than the sum of the van der Waals
radii [27] at 3.96 Å for an iodine–iodine interaction. With a
C5–I3–I2 bond angle of 168.01°, the interaction is consistent
with the σ-hole [28] of I3 interacting with the lone pairs on
I2. The remaining close contact of the tetramer is formed
between S1 and I2 with a distance of 3.615 Å—shorter than
Conclusions
Using X-ray crystallography and standard spectroscopic
techniques, we were able to correct an oversight in the lit-
erature. As shown in Scheme 1, the literature supposes that
the products obtained from iodination of 2-methylthioh-
phene are 2 and 3 as opposed to 2 and 4. The presence of
4 is confirmed by single crystal diffraction methods while
1
the absence of 3 is determined by the H NMR spectrum
of the crude product mixture. As iodinated compounds are
useful intermediates and starting material, we imagine that
1
3

Journal of Chemical Crystallography
compound 4, obtained by relatively mild methods, could
find use in the field of organic materials. The observed
halogen and chalcogen bonds will add to our understand-
ing of these non-covalent interactions and potentially find
applications in materials engineering [29–31], biological
applications [32–34], and recently in separation methods
[
35].
Supplementary Information
1
13
NMR spectra, H and C, for 3,4,5-triiodo-2-methyl thio-
phene. CCDC 1860825 contains the supplementary crys-
tallographic data for this paper; this data can be obtained
free of charge via http://www.ccd.cam.ac.uk/conts/retri
eving.html or from CCDC, 12 Union Road, Cambridge
CB21EZ, UK; Fax: +44-1223-336033; Email: deposit@
ccdc.cam.ac.uk.
Fig. 2 The crystal structure of 3,4,5-triiodo-2-methylthiophene (2)
with both the major and minor species shown superimposed (top) .
The structure of the major disorder species where C2–I3A and C5–
C1A bonds are not shown (bottom left); the structure of the minor
disorder species where C2–I3A and C5–C1A bonds are shown (bot-
tom right). Thermal ellipsoids are shown at 50% and hydrogen atoms
are omitted for clarity
Fig. 3 The tetramer of 4 with
halogen and chalcogen bonds
and bond lengths denoted
1
3

Journal of Chemical Crystallography
Fig. 4 Lateral short I1–I1
contacts of 3.771 Å showing a
zig-zag chain that propagates
parallel to [010] for 4
Acknowledgements DGP thanks Penn State Hazleton for funding in
the form of a Research Development Grant. JBB acknowledges support
from the National Science Foundation under Grant No. DMR-1455039.
10. Youm SG, Hwang E, Chavez CA, Li X, Chatterjee S, Lusker
KL, Lu L, Strzalka J, Ankner JF, Losovyj Y, Garno JC, Nest-
erov EE (2016) Polythiophene thin films by surface-initiated
polymerization: mechanistic and structural studies. Chem Mater
2
5
8(13):4787–4804. https://doi.org/10.1021/acs.chemmater.6b019
7
1
1
1. Díaz SA, Gillanders F, Jares-Erijman EA, Jovin TM (2015) Pho-
toswitchable semiconductor nanocrystals with self-regulating
photochromic Förster resonance energy transfer acceptors. Nat
Commun 6:6036. https://doi.org/10.1038/ncomms7036
References
1
2
3
4
5
6
.
.
.
.
.
.
Fitton P, Rick EA (1971) The addition of aryl halides to
tetrakis(triphenylphosphine)palladium(0). J Organomet Chem
2. Díaz SA, Menéndez GO, Etchehon MH, Giordano L, Jovin TM,
Jares-Erijman EA (2011) Photoswitchable water-soluble quantum
dots: pcFRET based on amphiphilic photochromic polymer coat-
ing. ACS Nano 5(4):2795–2805. https://doi.org/10.1021/nn103
2
8(2):287–291. https://doi.org/10.1016/S0022-328X(00)84578
-
7
Littke Adam F, Fu Gregory C (2002) Palladium-catalyzed
coupling reactions of aryl chlorides. Angew Chem Int Ed 41
2
43c
1
1
1
3. Fukaminato T, Hirose T, Doi T, Hazama M, Matsuda K, Irie M
(
22):4176–4211. https://doi.org/10.1002/1521-3773(20021
(
2014) Molecular design strategy toward diarylethenes that photo-
1
15)41:22%3C4176::AID-ANIE4176%3E3.0.CO;2-U
switch with visible light. J Am Chem Soc 136(49):17145–17154.
https://doi.org/10.1021/ja5090749
Racys DT, Sharif SAI, Pimlott SL, Sutherland A (2016) Silver(I)-
catalyzed iodination of arenes: tuning the Lewis acidity of N-iodo-
succinimide activation. J Org Chem 81(3):772–780. https://doi.
org/10.1021/acs.joc.5b02761
4. Nakashima T, Fujii R, Kawai T (2011) Regulation of folding
and photochromic reactivity of terarylenes through a host–guest
interaction. Chem A Eur J 17(39):10951–10957. https://doi.
org/10.1002/chem.201101495
Sevez G, Pozzo J-L (2011) Toward multi-addressable molecular
systems: efficient synthesis and photochromic performance of
unsymmetrical bisthienylethenes. Dyes Pigm 89:246–253. https
5. Patel DG, Walton IM, Cox JM, Gleason CJ, Butzer DR, Benedict
JB (2014) Photoresponsive porous materials: the design and syn-
thesis of photochromic diarylethene-based linkers and a metal-
organic framework. Chem Commun 50(20):2653–2656. https://
doi.org/10.1039/C3CC49666J
:
//doi.org/10.1016/j.dyepig.2010.03.018
Shinde AT, Zangade SB, Chavan SB, Vibhute AY, Nalwar YS,
Vibhute YB (2010) A practical iodination of aromatic compounds
by using iodine and iodic acid. Synth Commun 40(23):3506–
1
1
1
6. Yam VWW, Ko CC, Wu LX, Wong KMC, Cheung KK (2000)
Synthesis, crystal structure, and photochromic properties of rhe-
nium (I) complexes containing the spironathoxazine moiety. Orga-
nometallics 19(10):1820–1822
3
513. https://doi.org/10.1080/00397910903457332
Zolfigol MA, Khazaei A, Kolvari E, Koukabi N, Soltani H, Behju-
nia M, Khakyzadeh V (2009) HIO /KI: a new combination rea-
3
gent for iodination of aromatic amines and trimethylsilylation of
alcohols and phenols through insitu generation of iodine under
mild conditions. Arkivoc 13:200–210
7. Buckup T, Sarter C, Volpp H-R, Jäschke A, Motzkus M (2015)
Ultrafast time-resolved spectroscopy of diarylethene-based
photoswitchable deoxyuridine nucleosides. J Phys Chem Lett
7
8
.
.
De PK, Neckers DC (2012) Sulfur containing stable unsubstituted
heptacene analogs. Org Lett 14(1):78–81. https://doi.org/10.1021/
ol2028724
6
(23):4717–4721. https://doi.org/10.1021/acs.jpclett.5b01949
8. Yagai S, Ohta K, Gushiken M, Iwai K, Asano A, Seki S, Kikkawa
Y, Morimoto M, Kitamura A, Karatsu T (2012) Photoreversible
supramolecular polymerisation and hierarchical organization of
hydrogen-bonded supramolecular Co-polymers composed of dia-
rylethenes and oligothiophenes. Chem A Eur J 18(8):2244–2253.
https://doi.org/10.1002/chem.201103465
Li S, Tang J, Zhao Y, Jiang R, Wang T, Gao G, You J (2017)
Cu-catalyzed controllable C–H mono-/di-/triarylations of imi-
dazolium salts for ionic functional materials. Chem Commun
5
3(24):3489–3492. https://doi.org/10.1039/C7CC01076A
9
.
O’Connor MJ, Haley MM (2008) Synthesis and properties of
butyl-capped dehydrothieno[14]annulenes and their conver-
sion into terthiophenes. Org Lett 10(18):3973–3976. https://doi.
org/10.1021/ol801451x
1
9. Dolomanov OVB, Gildea LJ, Howard RJ, Puschmann JAK, H
(
2009) OLEX2: a complete structure solution, refinement and
analysis program. J Appl Cryst 42:339–341
1
3

Journal of Chemical Crystallography
2
2
0. Sheldrick GM (2008) A short history of SHELX. Acta Cryst A
the crystal state, the case of 2-trichloromethyl-3H-4-quinazoline
polymorphs and 1-methyl-2-trichloroacetylpyrrole–hirshfeld
surface analysis of chlorine halogen bonding. Cryst Growth Des
13(9):3913–3924. https://doi.org/10.1021/cg400584w
31. Metrangolo P, Resnati G, Pilati T, Liantonio R, Meyer F (2007)
Engineering functional materials by halogen bonding. J Polym
Sci Part A: Polym Chem 45(1):1–15. https://doi.org/10.1002/
pola.21725
6
4(1):112–122
1. Takahashi K, Ito I, Matsuki Y (1967) Proton magnetic resonance
spectra of methyliodothiophenes. Bull Chem Soc Jpn 40(3):605–
6
07. https://doi.org/10.1246/bcsj.40.605
2
2. Steinkopf W, Hanske W (1937) Studien in der thiophenreihe.
XXXIV. Über die Jodderivate des 2-Thiotolens. Justus Liebigs
Annalen der Chemie 527(1):264–271. https://doi.org/10.1002/
jlac.19375270118
32. Guo P, Paul A, Kumar A, Farahat AA, Kumar D, Wang S, Boykin
DW, Wilson WD (2016) The thiophene “Sigma-Hole” as a con-
cept for preorganized, specific recognition of G⋅C base pairs in the
DNA minor groove. Chem A Eur J 22(43):15404–15412. https://
doi.org/10.1002/chem.201603422
2
2
3. Gronowitz S, Svensson A (1986) On the ring-opening of some
3
-lithiobithienyls and 3′-lithio-α-terthienyls. Isr J Chem 27(1):25–
2
8. https://doi.org/10.1002/ijch.198600004
4. Allen FH, Kennard O, Watson DG, Brammer L, Orpen AG, Taylor
R (1987) Tables of bond lengths determined by x-ray and neutron
diffraction. Part 1. Bond lengths in organic compounds. J Chem
Soc Perkin Trans 2:S1–S19
33. Wilcken R, Zimmermann MO, Lange A, Joerger AC, Boeck-
ler FM (2013) Principles and applications of halogen bond-
ing in medicinal chemistry and chemical biology. J Med Chem
56(4):1363–1388. https://doi.org/10.1021/jm3012068
34. Cody V, Murray-Rust P (1984) Iodine⋯X(O, N, S) intermolecu-
lar contacts: models of thyroid hormone protein binding interac-
tions using information from the cambridge crystallographic data
files. J Mol Struct 112(3):189–199. https://doi.org/10.1016/0022-
2860(84)85061-9
2
2
5. Cavallo G, Metrangolo P, Milani R, Pilati T, Priimagi A, Resnati
G, Terraneo G (2016) The halogen bond. Chem Rev 116(4):2478–
2
601. https://doi.org/10.1021/acs.chemrev.5b00484
6. Vogel L, Wonner P, Huber SM (2018) Chalcogen bonding:
an overview. Angew Chem Int Ed. https://doi.org/10.1002/
anie.201809432 In press.
2
2
7. Bondi A (1964) van der Waals volumes and radii. J Phys Chem
35. Peluso P, Mamane V, Aubert E, Dessì A, Dallocchio R, Dore
A, Pale P, Cossu S (2016) Insights into halogen bond-driven
enantioseparations. J Chromatogr A 1467:228–238. https://doi.
org/10.1016/j.chroma.2016.06.007
6
8(3):441–451. https://doi.org/10.1021/j100785a001
8. Clark T, Hennemann M, Murray JS, Politzer P (2007) Halogen
bonding: the σ-hole. J Mol Model 13(2):291–296. https://doi.
org/10.1007/s00894-006-0130-2
2
9. Noh J, Jung S, Koo DG, Kim G, Choi KS, Park J, Shin TJ, Yang
C, Park J (2018) Thienoisoindigo-based semiconductor nanow-
ires assembled with 2-bromobenzaldehyde via both halogen and
chalcogen bonding. Sci Rep 8(1):14448. https://doi.org/10.1038/
s41598-018-32486-z
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jurisdictional claims in published maps and institutional affiliations.
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0. Rybarczyk-Pirek AJ, Chęcińska L, Małecka M, Wojtulewski S
(
2013) Intermolecular interactions of trichloromethyl group in
Affiliations
Dinesh G. Patel1 · Eric D. Sylvester · Nicholas R. LeValley · Travis B. Mitchell · Jason B. Benedict
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Department of Chemistry, The Pennsylvania State
University, Hazleton, PA 18202, USA
Department of Chemistry, University at Buffalo, Buffalo,
NY 14228, USA
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