Further evidence on the importance of fluorous-fluorous interactions in supramolecular chemistry: A combined structural and computational study

Article abstract of DOI:10.1021/acs.cgd.5b00254

The solid-state structures of CF₃(CF₂)₅CH₂CO₂H and a fluorous triazole are reported, both of which display a wide variety and large number of noncovalent interactions in their packing. The solid-state structure of CF₃(CF₂)₅CH₂CO₂H is stabilized by multiple F···F contacts but only one C-H···F-C interaction, as well as O-H···O and C-H···O hydrogen bonds. In contrast to other reported structures, the torsion angles in the fluorous chain are close to 180°, which means that the fluorine atoms are eclipsed. A DFT study of the interactions in both compounds show that F···F interactions, along with stacking and C-H···F and C-H···O contacts, are individually weakly energetically stabilizing, but collectively, they can give rise to interaction energies of up to 13 kcal mol^-1. A topological approach to the interactions using atoms-in-molecules (AIM) theory reveals that there are bond critical points between the C-F···F-C interactions as well as C-F···H-C interactions that are not recognized when using only the van der Waals distances.

Full text of DOI:10.1021/acs.cgd.5b00254

Subscriber access provided by UB + Fachbibliothek Chemie | (FU-Bibliothekssystem)
Article
Further Evidence on the Importance of Fluorous-Fluorous Interactions in
Supramolecular Chemistry: A Combined Structural and Computational Study
Harrison Omorodion, Brendan Twamley, James A. Platts, and Robert James Baker
Cryst. Growth Des., Just Accepted Manuscript • DOI: 10.1021/acs.cgd.5b00254 • Publication Date (Web): 01 May 2015
Downloaded from http://pubs.acs.org on May 3, 2015
Just Accepted
“Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted
online prior to technical editing, formatting for publication and author proofing. The American Chemical
Society provides “Just Accepted” as a free service to the research community to expedite the
dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts
appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been
fully peer reviewed, but should not be considered the official version of record. They are accessible to all
readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered
to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published
in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just
Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor
changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers
and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors
or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
Crystal Growth & Design is published by the American Chemical Society. 1155
Sixteenth Street N.W., Washington, DC 20036
Published by American Chemical Society. Copyright © American Chemical Society.
However, no copyright claim is made to original U.S. Government works, or works
produced by employees of any Commonwealth realm Crown government in the course
of their duties.

Page 1 of 28
Crystal Growth & Design
1
2
3
4
5
6
7
8
9
Further Evidence on the Importance of Fluorousꢀ
Fluorous Interactions in Supramolecular Chemistry:
A Combined Structural and Computational Study
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Harrison Omorodion1, Brendan Twamley1, James A. Platts2 and Robert J. Baker*1
1 School of Chemistry, University of Dublin, Trinity College, Dublin 2, Ireland
2 School of Chemistry, Main Building, Cardiff University, Park Place, Cardiff, CF10 3AT, U.K.
KEYWORDS: Nonꢀcovalent interactions; fluorousꢀfluorous interactions; DFT; AIM
ABSTRACT. The solid state structures of CF3(CF2)5CH2CO2H and a fluorous triazole are
reported, both of which display a wide variety and large number of nonꢀcovalent interactions in
their packing . The solid state structure of CF3(CF2)5CH2CO2H is stabilized by multiple F…F
contacts but only one C—H…F—C interaction, as well as O—H…O and C—H…O hydrogen
bonds. In contrast to other reported structures, the torsion angles in the fluorous chain are close
to 180° which means that the fluorine atoms are eclipsed. A DFT study of the interactions in
both compounds show that F…F interactions, along with stacking and C—H…F and C—H…O
contacts, are individually weakly energetically stabilizing, but collectively can give rise to
interaction energies of up to 13 kcal molꢀ1. A topological approach to the interactions using
ACS Paragon Plus Environment
1

Crystal Growth & Design
Page 2 of 28
1
2
3
4
5
6
7
8
9
AtomsꢀinꢀMolecules (AIM) theory reveals that there are bond critical points between the C—
F…F—C interactions as well as C—F…H—C interactions that are not recognized when only
using the van der Waals distances.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Introduction
There are a plethora of nonꢀcovalent interactions that synthetic chemists can use to design
supramolecular structures.1,2 Whilst hydrogen bonding continues to be a mainstay of such
interactions, there is a growing realization that halogens interactions can also be utilized.
Consequently there is now much interest in the halogen bond, defined recently by IUPAC,3 in
fields as diverse as crystal engineering,4,5,6 liquid crystals,7 molecular conductors8 molecular
recognition agents,9,10,11,12,13,14,15 catalysis16,17 and medicinal chemistry.18,19,20 Perhaps of most
surprise is that F…F nonꢀcovalent interactions are known to be stabilizing and can give a
significant energy contribution to the structures, as Pauling’s principle21 state that the attractive
interatomic dispersion forces would be low due to the low polarisability of fluorine.22 However,
in recent years a number of studies have shown that these type of interactions do exist and are
not simply due to crystal packing. There are now a growing number of examples of F…F
interactions being utilized as crystal engineering for applications in materials
chemistry23,24,25,26,27,28,29,30 or in catalysis.31
Given the importance and potential use of C—F…F—C interactions, it is imperative to ascertain
the conditions where these have a stabilizing interaction and situations where these are due only
to packing forces. There are three recognized types of F…F interactions (Chart 1); Type I are the
most contentious in terms of delineating between crystal packing and stabilizing,4 whilst Type III
ACS Paragon Plus Environment
2

Page 3 of 28
Crystal Growth & Design
1
2
3
4
5
6
7
8
9
have recently been described in restricted geometries afforded by cyclohexane or naphthalene
frameworks.32 We recently reported on a systematic structural and computational study on three
distinct molecules, each featuring a CF3(CF2)5 ponytail, vis CF3(CF2)5CH(Me)CO2H, 1,
CF3(CF2)5(CH2)4(CF2)5CF3 and (CF3(CF2)5CH2CH2)3P=O where Type II C—F…F—C
interactions were present.33 Intriguingly we noted that in the carboxylic acid there were a number
of C—H...F—C interactions but in the alkane only C—F…F—C interactions were present. This
can be contrasted to the structure of 1,2,3,4ꢀtetrafluorobenzene, where there is a preference for
C—H…F—C interactions over C—F…F—C interactions.34 This poses an interesting question as
to which are the more stabilizing interaction. It is possible that more or stronger dipoleꢀdipole
interactions between nonꢀfluorous neighbors, leads to segregation of the fluorous domains (a
form of molecular xenophobia) or a steric dominated interaction, specifically the larger radius of
F vs. H determines the interactions. It is noteworthy that such C—H…F—C hydrogen bonds
have only recently been recognized and are developing a strong research interest by both theory
and experiment35,36,37,38,39,40 but C—F…F—C interactions are not so well developed.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
In order to answer this we have sought to (a) change the substitution pattern on the methylene
carbons in the acid, as this is synthetically rather straightforward and (b) explore what happens
when the strongly hydrogen bonded carboxylic acid is substituted for a functional group with
less propensity of being involved in hydrogen bonding such as an azide function. In this work we
report on the structure of the complex CF3(CF2)5CH2CO2H, 2, as the removal of the methyl
group should reduce the steric demand of the compound and thus allow a closer packing of the
fluorous chains. Furthermore, we have structurally characterized an unusual rearrangement
product from the synthesis of CF3(CF2)5CH2CH2N3, viz, a 1,4ꢀbis(perfluoroalkly)triazole, 3;
triazoles have become a useful platform for the characterization of supramolecular interactions.41
ACS Paragon Plus Environment
3

Crystal Growth & Design
Page 4 of 28
1
2
3
4
5
6
7
8
9
For instance, the 1,4ꢀdiphenylꢀ1,2,3ꢀtriazole fragment has been used as a scaffold to explore
halogen substitution in the orthoꢀ and paraꢀposition of the phenyl group to explore the relative
strengths of the C—X…H bonding and it was concluded that the C—F…H interactions are
stronger than the C—Cl…H interaction.42 We may be able to begin to shed light on the factors
that influence C—F…F—C and C—F…H—C interactions, which would be useful in the
multitude of applications of these interactions.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
θ1 = θ2
θ1 ≈ 180°, θ2 ≈ 90° θ1 ≈ θ2 ≈ 90°
Chart 1. Classification of halogenꢀhalogen interactions.
Results and Discussion
Synthesis and Structures of 2 and 3. The complex CF3(CF2)5CH2CO2H, 2, was prepared by
oxidation of the corresponding alcohol with Jones Reagent, as described in the literature.43
ACS Paragon Plus Environment
4

Page 5 of 28
Crystal Growth & Design
1
2
3
4
5
6
Crystallization from chloroform afforded Xꢀray quality crystals and the packing diagram is
shown in Figure 1.
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Figure 1. Packing diagram of 2 viewed down the c axis.
The complex exists as the typical hydrogen bonded dimer and there are a number of C—
F…F—C contacts that are shorter than the van der Waals radii. There are type I interactions
between the CF3 groups on the chains which extend in the c plane (dF..F = 2.803 and 2.903 Å,
∠CꢀF…F = 135° and 158°). Bifurcated “threeꢀpoint interactions” (dF..F = 2.908 and 2.923;
∠F…F…F = 54o) are also present between the ponytails. In contrast to 1, there are no short C—
F...H—C interactions (dFꢀH < 2.66 Å)44 in this complex as the hydrogens are involved in C—
H…O hydrogen bonding to a carboxylate group. This indicates that the C—H...O interaction is
stronger than a C—H...F—C interaction, and in accord with other examples in the literature. The
bond lengths within the fluorous domain are identical to that seen in 1, but the C—C and C—O
ACS Paragon Plus Environment
5

Crystal Growth & Design
Page 6 of 28
1
2
3
4
5
6
7
8
9
bonds of the acid fragment are slightly different {C—C: 1 – 1.595(6) Å; 2 – 1.510(3) Å; C=O: 1
– 1.379(5) Å; 2 – 1.235(2) Å; C—OH: 1 – 1.381(5) Å; 2 – 1.293(2) Å} and this is also reflected
in the changes in the C=O stretch in the infrared spectra (1: 1772 cmꢀ1; 2: 1714 cmꢀ1;
CH3(CH2)7CO2H45: 1712 cmꢀ1). Interestingly, there is a significant difference in the F—C—C—
F torsion angles, as in 1, and indeed 148 of 149 structurally characterized examples in the
Cambridge Structural Database46 that feature at least a CF3(CF2)5 chain, the torsion angles are
lower compared to hydrocarbon chains. This is to relieve electrostatic interactions between two
fluorine groups, although other factors may also be involved, and results in a slight twist of the
fluorocarbon chain.47,48,49,50,51,52,53,54 However in 2 this is not the case and the fluorine atoms are
in an eclipsed conformation. The only other example in the database that has eclipsed F atoms is
the structure of heptyl 2ꢀ(perfluorohexyl)ethyl ketone, but no comment was made about this in
the paper.55 It has been reported that C—F…F—C interactions can be observed by small shifts in
the infrared spectrum,56 but the infrared and Raman spectra of 2 and 3 are identical in the C—F
stretching and bending regions (spectroscopic data are included in the ESI). DFT calculations of
2 suggest that the twisted conformation is indeed the most stable, with the ‘untwisted’ conformer
at 96 kJ molꢀ1 higher in energy. Given the unusual nature of this compound, we have explored
the weak interactions using a combination of DFT and AtomsꢀInꢀMolecules (vide infra).
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
The triazole, 3, was synthesized as a minor byproduct from the treatment of
CF3(CF2)5CH2CH2I with NaN3 in DMF, according to the literature.57 Cooling the crude mixture
o
1
to ꢀ35 C afforded a few crystals that were structurally characterized. Careful H NMR
spectroscopic analysis of the reaction mixture showed that 3 is consistently formed in low yield;
the spectroscopic data confirm the formulation of 3, particularly the unique CHF group. The
mechanism of formation is rather unclear but dissolution of CF3(CF2)5CH2CH2I in DMF affords
ACS Paragon Plus Environment
6

Page 7 of 28
Crystal Growth & Design
1
2
a number of products,58 one of which we can also identify as the alcohol CF3(CF2)5CH2CH2OH.
It is also possible that a dehydrohalogenation step occurs upon reaction of the perfluoroalkyl
halide with DMF;59 this may give rise to the unique CHF moiety. Clearly the reaction is more
complex than described, and presumably an alkyne must be eventually generated to form the
triazole via a Huisgen 1,3ꢀdipolar cycloaddition reaction. It’s also worth noting that similar azide
has been reported to form triazoles via the copper catalyzed click reaction in good yield and with
an intact fluorous group.60,61 The structure of 3 is shown in Figure 2. The most notable feature is
the replacement of one C—F bond for a C—H bond in one of the Rf chains. The metric
parameters within the heterocyclic ring are as expected from a survey of the Cambridge
Structural Database and the bond lengths within the ponytails are also normal, apart from the
CHF group, where the C—F bond is the longest at 1.401(6) Å. It is also noteworthy that the F—
C—C—F torsion angles are as expected for a fluorous chain, imparting a twist to the chain.
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Figure 2. The molecular structure of 3.
The packing of 3 is shown in Figure 3, and a plethora of nonꢀcovalent interactions are clear.
There are number of C—F…F—C interactions that segregate the fluorous and non fluorous
domains. There are long contacts between the ends of the molecule (dF…F = 2.915 Å) and
ACS Paragon Plus Environment
7

Crystal Growth & Design
Page 8 of 28
1
2
3
4
5
6
7
8
9
bifurcated “threeꢀpoint interactions” (dF..F = 2.679 and 2.781 Å; ∠F…F…F = 99.2°) that connect
the chains. There are C—F…H—C interactions present from the CHF carbon (dH…F = 2.463 and
2.503 Å) which unusually exist in a bifurcated arrangement between three chains. C—H...N
hydrogen bonds between the triazole backbone and a second triazole N2 nitrogen (dC..N = 3.235)
are also present; it has been noted that this C—H bond is highly polarized and can be as strong as
as amides.41 The CH2 groups on the ‘normal’ Rf chain are also involved in hydrogen bonding to
the other triazole nitrogen (dC.. N = 3.662) to form chains perpendicular to the plane depicted in
Figure 3.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Figure 3. Packing diagram of 3 viewed down the ab plane.
Given the unusual structure of 2 compared to 3 we were interested to see if there were any
differences in the solid state 19F NMR spectra that may be related to the C—F…F—C
interactions (spectroscopic data are included in the ESI). The spectrum recorded for 2 was very
broad, likely due to extensive dipolar couplings,62 but in 1 the signals were quite sharp. However
as noted previously,63 further work is required to attain a level of accuracy on a par with NMR
crystallography.64
ACS Paragon Plus Environment
8

Page 9 of 28
Crystal Growth & Design
1
2
3
4
Computational studies on 2 and 3.
5
6
7
8
9
One method of quantifying the interactions in the solid state is to calculate the interaction
energies between individual molecules. We have recently studied some examples via this
technique33 so include a DFT and QTAIM description of the two complexes herein. A series of
dimers was extracted from the crystal structures of 2 and 3 by applying individual symmetry
operations to the entire molecule, with interaction energies (calculated without altering
geometry) reported in Tables 1 and 2. Using this methodology, five dimers were extracted from
the crystal structure of 2. The first, 2a, contains two hydrogen bonds linking carboxylic acid
groups and no close C—F…F—C contacts. 2b contains only C—H…O hydrogen bonds between
the carboxylic acid and the methylene group. 2c however does exhibit C—F…F—C contacts of
length 2.854, 2.922, and 2.861 Å, while 2d and 2e contains just one C—F…F—C contact at
2.913 Å and 2.803 Å respectively. As expected the hydrogen bonded dimer 2a is very strongly
stabilised; for comparison the interaction energy for the same dimer in 1 was ꢀ13.23 kcal molꢀ1.
2c is only weakly stabilised despite its numerous close contacts, but this data confirms that the
threeꢀpoint interaction motif discussed above is stable; the comparable energies for 1 was ꢀ1.69
kcal/mol. Binding of 2d and 2e is very weak indeed with a binding energy close to that we
previously calculated for (CF4)2.33
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Topological analysis using an Atomsꢀinꢀmolecules approach have also been conducted and the
results are shown in Table 1. Strictly speaking, since the dimers considered here are not at their
optimal geometry, the presence of a bond critical point and associated atomic interaction line
cannot be used as evidence of bonding. However, we prefer this approach here as it should better
preserve the interactions present in the solid state. Dimer 2a displays only the hydrogen bonds of
the acid function, and the electron density at the bond critical point ρbcp is slightly smaller than
ACS Paragon Plus Environment
9

Crystal Growth & Design
Page 10 of 28
1
2
3
4
5
6
that seen in 1 (0.048 au), in line with the slightly smaller interaction energy. C—F…F—C
interactions are observed in dimer 2c, and again the electron density at the bond critical point
7
8
9
ρbcp is of the same order of magnitude as in 1, indicating that these interactions are not due to
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
crystal packing effects and do have an important contribution to the stabilization of the dimers.
Interestingly, AIM analysis finds one C—H…F—C interaction that was not observed by
consideration of the van der Waals radii analysis, although it is rather weak (c.f. ρbcp = 0.0045 in
1). Dimers 2d and 2e on the other hand are likely due to Type I interactions.
Recent work65 has shown that intramolecular X…X interactions in perhaloethanes are
destabilizing, despite the presence of a bond critical point and bond path, through use of the
Interacting Quantum Atoms (IQA) approach, although no such critical points were found for
fluoroꢀ compounds. Unfortunately, the computational requirements of this approach prohibit its
use for the dimers we consider here. However, our data suggest that the intermolecular F…F
contacts seen here are stabilizing, since dimers 2d and 2e are predicted to be weakly bound and
contain only F…F contacts between molecules. Further detail on the origin of this stabilization
comes from data reported in Table S1 (see ESI), which reports the contribution of dispersion to
the overall interaction energy. For the purely F…F contacts in 2d and 2e, the dispersion
contribution is larger than the overall interaction energy, such that it accounts for all
stabilization: presumably electrostatic and exchange effects are weakly repulsive in the crystal
geometry. The same pattern is observed for dimers 2b and 2c, and only in the hydrogen bonded
dimer 2a do we observe dispersion contribution smaller in magnitude than the overall interaction
energy.
ACS Paragon Plus Environment
10

Page 11 of 28
Crystal Growth & Design
1
2
3
4
Table 1. Interaction energies (kcal molꢀ1) and ρbcp values (au) of dimers of 2 taken from the
5
crystal structure.
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
IE = ꢀ14.7
OꢀH...O: 0.038 (x2)
2a
IE = ꢀ2.9
CꢀH…O: 0.008
H…H: 0.003
F…O: 0.003
2b
IE = ꢀ4.0
F…F: 0.006
0.005 (x5)
CꢀH…F: 0.002
F…O: 0.002 (x2)
2c
ACS Paragon Plus Environment
11

Crystal Growth & Design
Page 12 of 28
1
2
3
4
5
6
IE = ꢀ0.6
7
8
9
F…F: 0.004
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
2d
IE = ꢀ1.5
F…F: 0.006
2e
The same process applied to 3 results in 5 dimers generated by symmetry operations:
interaction energy and ρbcp values for each are reported in Table 2. It is immediately apparent
that dimer 3a, which contains a C—H…N hydrogen bond between triazole rings, is almost as
strongly stabilized as the dimer 2a, which has two classical O—H…O Hꢀbonds. Topological
analysis indicates that the C—H…N has substantial electron density, but that this is only oneꢀ
third of that seen in O—H…O in 2a. Instead, the large stabilization of this dimer arises just as
much from numerous other interactions, including a weaker C—H…N contact between
methylene and triazole, two C—H…F contacts and 12 F…F ones. Collectively, ρbcp values of all
contacts sum to 0.050 au, less than that in 2a but of similar magnitude.
ACS Paragon Plus Environment
12

Page 13 of 28
Crystal Growth & Design
1
2
3
4
5
6
7
8
9
Dimer 3b contains just one F…F contact, and its interaction energy of just 1.1 kcal/mol
reflects this fact. In contrast, 3c is strongly stabilized, but despite the short distance between and
parallel orientation of triazole rings, there is little contribution of stacking interactions to the
overall interaction. Two C…C contacts are present, but these connect methylene with triazole
and exhibit small ρbcp values. Instead, C—H…F and especially F…F contacts dominate 3c. It is
notable that analysis based on the geometry of the crystal structure, using the default setting of
Mercury,66 picks out only two F…F contacts in this structure, assigns stacking as C—H…π
interactions, and present no evidence for C—H…F contacts. 3d and 3e are also strongly
stabilized, in both cases through a combination of πꢀstacking, C—H…F and F…F interactions.
The former contains F…N contacts as well as numerous F…F, whereas the latter is the only one
found here that exhibits the pattern of critical points expected of πꢀstacking as seen in the
benzene dimer and related complexes.67 Once again, dispersion dominates these dimers, since in
each dimer this is larger in magnitude than the overall interaction energy (Table S1).
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
ACS Paragon Plus Environment
13

Crystal Growth & Design
Page 14 of 28
1
2
3
4
Table 2. Interaction energies (kcal molꢀ1) and ρbcp values (au) of dimers of 3 taken from the
5
crystal structure.
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
IE = ꢀ14.2
CꢀH…N: 0.013
0.006
CꢀH…F: 0.005, 0.003
F…F: 0.003 (x2)
0.002 (x7)
0.001 (x3)
3a
IE = ꢀ1.11
F…F: 0.005
3b
ACS Paragon Plus Environment
14

Page 15 of 28
Crystal Growth & Design
1
2
3
4
5
6
IE = ꢀ7.8
7
8
9
C…C: 0.001 (x2)
CꢀH…F: 0.002 (x2)
F…F: 0.008 (x2)
0.004 (x2)
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
0.003 (x4)
3c
0.002 (x6)
0.001 (x2)
IE = ꢀ11.5
F…N: 0.004, 0.003,
0.002, 0.001
CꢀH…F: 0.008, 0.004
0.002 (x3)
F…F: 0.007 (x2)
0.003 (x4)
3d
0.002 (x3)
0.001
ACS Paragon Plus Environment
15

Crystal Growth & Design
Page 16 of 28
1
2
3
4
5
6
IE = ꢀ12.8
7
8
9
N…N: 0.006
CꢀH…N: 0.006 (x2)
F…F: 0.007 (x2)
0.003 (x2)
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
3e
Conclusion
In conclusion we have isolated and structurally characterized two examples of compounds that
feature fluorinated ponytails and have characterized the nonꢀcovalent interactions that are
present. In the perfluorinated carboxylic acid, CF3(CF2)5CH2CO2H, Xꢀray and computational
data show that the order of stabilizing interactions are O—H...O, C—H...O, C—F... F—C and no
C—F...H—C interactions are present. However, a topological analysis does find one weak C—
F...H—C interaction. There is an unusual ‘untwisting’ of the perfluorochain that has not been
commented upon previously and it may be that the untwisting increases the number of C—
F...F—C interactions at the expense of C—F...H—C electrostatic interactions; clearly further
work is required to fully understand this, but the energies of these interactions could be of the
same order of magnitude. The structure of a triazole, synthesized as a minor byproduct shows the
normal twisted perfluorinated chain with a cornucopia of weak interactions. Computational
studies reinforce previous work from us and others that the C—F...F—C interactions are present
ACS Paragon Plus Environment
16

Page 17 of 28
Crystal Growth & Design
1
2
3
4
5
6
and stabilizing. Finally this work adds some credence to the idea that steric interactions do play a
role in the nonꢀcovalent interactions present in these compounds.
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Experimental
1H, 13C{1H} and 19F NMR spectra were recorded on a Bruker AV400 spectrometer operating at
400.23 MHz, 155.54 MHz and 376.55 MHz respectively, or a Bruker Avance II 600 NMR with
a TCI cryoprobe spectrometer operating at 150.92 MHz (13C) and were referenced to the residual
1H and 13C resonances of the solvent used or external CFCl3. 19F NMR assignments were
confirmed using COSY experiments. IR spectra were recorded on a Perkin Elmer Spectrum One
spectrometer with attenuated total reflectance (ATR) accessory. Raman spectra were obtained
using 785ꢀnm excitation on a Renishaw 1000 microꢀRaman system in sealed capillaries. Mass
spectra were measured on a MALDI QTOF Premier MS system. Xꢀray crystallography data were
measured on a Rikagu Saturn and on a Bruker Apex diffractometer. The structure was solved by
direct methods and refined by least squares method on F2 using the SHELXTL program
package.68 Crystal data, details of data collections and refinement are given in Table 3. All
compounds and solvents were obtained from commercial sources and used as received.
DFT calculations were carried out in Gaussian0969 with the dispersion corrected B97D
functional70 and def2ꢀTZVP basis set71 used in previous work, and taking advantage of density
fitting to make larger calculations viable where possible. All calculations of interaction energy
used the counterpoise method to account for basis set superposition energy.72 Converged
molecular orbitals were obtained from these calculations and used for topological analysis of the
resulting electron density using the AIMAll package.73
ACS Paragon Plus Environment
17

Crystal Growth & Design
Page 18 of 28
1
2
3
4
5
6
7
8
1H,1H-perfluoroctanoic acid, 2. The crude product was recrystallized from DCM to yield the
colorless plateꢀlike crystals. (0.90 g, 53%). Spectroscopic data are in accord with the literature
(ESI).74
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
4-(1,2,2,3,3,4,4,5,5,6,6,6-dodecafluorohexyl)-1-(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl)-
1H-1,2,3-triazole, 3. 1H,1H,2H,2Hꢀperfluorooctyl iodide (5.82 g, 12 mmol) was dissolved in
DMF (60 ml). NaN3 (1.6 g, 25 mmol) was added and refluxed for 12 h. The mixture was filtered
and the filtrate was extracted with ether (3 x 40 ml). The organic extracts were combined and
dried with MgSO4 and concentrated to afford a brown oil. Recrystallization from DCM resulted
0
in Xꢀray quality crystals of 3 as a side product. (1.20 g, 15 %). M.Pt. = 90ꢀ92 C. IR ṽ (cmꢀ1) =
3121 (s, C=C); 2920 (w, CꢀH), 1553 (s, NꢀH), 1468, 1363 (w, CꢀH), 1320 (s, CꢀN), 1230, 1187,
1139, 1107 (s, C–F), 1080, 1047, 1028, 991, (m, C–F), 870, 816, 723, (w, CꢀH), 692 646 (m, Cꢀ
1
2
3
H). H NMR (400 MHz, CDCl3) δ (ppm) 7.91 (s, 1H, HC=C); 6.20 (ddd, JHꢀF = 25 Hz, JHꢀF
=
18 Hz, JH,H = 7 Hz, CHF); 4.77 (t, 2 H, JHꢀH = 7 Hz, CH2CH2N); 2.88 (m, 2 H, JHꢀF = 19 Hz, JH,H
= 7 Hz, CH2CF2) 13C NMR (100 MHz, CDCl3) δ (ppm) 137.8 (1C, NC=C); 124.6 (1C, NC=C);
118.8 (2C, CF3) 116.8, 115.3, 110.2, 107.9, (10C, CF2); 83.2ꢀ81.3 (1C, CHF); 43.0 (1 C, CH2N);
32.5 (CH2CF2); 31.3 (CH2CF2). 19F NMR [377 MHz, CDCl3]: δ ꢀ81.45 (s, CF3); ꢀ114.59 (s,
CF2CH2); ꢀ120.3 (s, CF2CHF); ꢀ121.1 (s, CF2CHF); ꢀ122.60 (m, CF3CF2CF2); ꢀ123.54 (m,
CF3CF2CF2CF2); 124.11 (s, CF3CF2CF2CF2CF2); 125.76 (s, CHF); 126.74 (m, CF3CF2). MS
(ESIꢀ) m/z: 715.0163 [M+H, 100%]; HRMS (ESI+) calculated for C16H6F25N3: 715.0163, found:
716.0240
ACS Paragon Plus Environment
18

Page 19 of 28
Crystal Growth & Design
1
2
3
4
Table 3. Crystal Data and Refinement Parameters for Complexes 2 and 3
5
6
7
8
9
2
3
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
CCDC Number
1045079
C8H3F13O2
378.10
Triclinic
P ꢀ1
1045080
C16H6F25N3
715.24
Empirical formula
Formula weight
Crystal system
Monoclinic
C2/c
Space Group
a (Å)
5.1220(10)
6.1827(12)
18.005(4)
88.91(3)
87.15(3)
80.56(3)
561.7(2)
2
45.931(3)
5.4147(4)
19.6834(16)
90
b (Å)
c (Å)
α (o)
β (o)
108.222(5)
90
γ (o)
V (Å3)
4649.8(6)
8
Z
Density (calculated) (Mg/m3)
2.235
2.043
Absorption coefficient (mmꢀ1) 0.295
2.479
F(000)
368
2784
Crystal size
0.300 x 0.240 x 0.100
0.190 x 0.160 x 0.060
2.025 to 64.272
ꢀ53≤h≤48
ꢀ6≤k≤6
Theta range for data collection 2.265 to 27.489
Limiting Indices
ꢀ6<=h<=6
ꢀ6<=k<=7
ꢀ23<=l<=23
8368
ꢀ22≤l≤22
20881
Reflections collected
Independent reflections
2412 [R(int) = 0.0284]
3868 [R(int) = 0.0659]
ACS Paragon Plus Environment
19

Crystal Growth & Design
Page 20 of 28
1
2
3
4
5
6
Completeness to theta (%)
Refinement method
95.3
91.6
Fullꢀmatrix leastꢀsquares on F2 Fullꢀmatrix leastꢀsquares on F2
7
8
9
Data / restraints / parameters
Goodnessꢀofꢀfit on F2
2412 / 0 / 212
3868 / 0 / 397
1.171
1.040
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Final R indices [I>2sigma(I)]
R indices (all data)
R1 = 0.0479, wR2 = 0.1398
R1 = 0.0496, wR2 = 0.1415
R1 = 0.0672, wR2 = 0.1736
R1 = 0.1013, wR2 = 0.1949
0.668 and ꢀ0.305
Largest diff. peak and hole 0.425 and ꢀ0.307
(e.Åꢀ3)
ASSOCIATED CONTENT
AUTHOR INFORMATION
Corresponding Author
* Tel: +353ꢀ1ꢀ8963501. Fax: +353ꢀ1ꢀ6712826. Eꢀmail: bakerrj@tcd.ie
Author Contributions
The manuscript was written through contributions of all authors. All authors have given approval
to the final version of the manuscript.
ACKNOWLEDGMENT
RJB and HO thanks the Environmental Protection Agency for funding this work (EPAꢀ2012ꢀ
WRMꢀPhDꢀ7). JAP is grateful to Advanced Research Computing @ Cardiff (ARCCA) for
computing facilities.
Supporting Information. Full crystallographic descriptions (CIF) and spectroscopic details.
This material is available free of charge via the Internet at http://pubs.acs.org.
ACS Paragon Plus Environment
20

Page 21 of 28
Crystal Growth & Design
1
2
3
4
References
5
6
7
8
9
(1) Lehn, J. ꢀM. Supramolecular Chemistry. Concepts and Perspectives; VCH, Weinheim,
Germany, 1995.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(2) Lehn, J. ꢀM. Angew. Chem., Int. Ed. 1988, 27, 89–112.
(3) Desiraju, G. R.; Ho, P. S.: Kloo, L.; Legon, A. C.; Marquardt, R.; Metrangolo, P.;
Politzer, P.; Resnati, G.; Rissanen, K.; Pure Appl. Chem. 2013, 85, 1711–1713.
(4) Mukherjee, A.; Tothadi, S.; Desiraju, G. R. Acc. Chem. Res. 2014, 47, 2514–2524.
(5) Troff, R. W.; Makela, T.; Topic, F.; Valkonen, A.; Raatikainen, K.; Rissanen, K. Eur. J.
Org. Chem. 2013, 1617ꢀ1637.
(6) Priimagi A.; Cavallo G.; Metrangolo P.; Resnati G. Acc. Chem. Res. 2013, 46, 2686ꢀ2695.
(7) Nguyen, H. L.; Horton, P. N.; Hursthouse, M. B.; Legon, A. C.; Bruce, D. W. J. Am. Chem.
Soc. 2004, 126, 16−17.
(8) Lieffrig, J.; Le Pennec, R.; Jeannin, O.; AubanꢀSenzier, P.; Fourmigue, M. CrystEngComm
2013, 15, 4408−4412.
(9) Robinson, S. W.; Mustoe, C. L.; White, N. G.; Brown, A.; Thompson, A. L.; Kennepohl,
P.; Beer, P. D., J. Am. Chem. Soc. 2015, 137, 499−507.
(10) Mullaney, B. R.; Partridge, B. E.; Beer, P. D. Chem. Eur. J. 2015, 21, 1660ꢀ1665.
ACS Paragon Plus Environment
21

Crystal Growth & Design
Page 22 of 28
1
2
3
4
5
6
7
8
(11) Langton, M. J.; Robinson, S. W.; Marques, I.; Felix, V.; Beer, P. D. Nature Chem. 2014,
6, 1039ꢀ1043.
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(12) Jungbauer, S. H.; Bulfield, D.; Kniep, F.; Lehmann, C. W.; Herdtweck, E.; Huber, S.
M. J. Amer. Chem. Soc. 2014, 136, 16740ꢀ16743.
(13) Erdelyi, M. Chem. Soc. Rev. 2012, 41, 3547−3557.
(14) Carlsson, A.ꢀC. C; Grafenstein, J.; Budnjo, A.; Laurila, J. L; Bergquist, J.; Karim, A.;
Kleinmaier, R.; Brath, U.; Erdelyi, M. J. Amer. Chem. Soc. 2012, 134, 5706ꢀ5715.
(15) Zapata, F.; Caballero, A.; White, N. G.; Claridge, T. D. W.; Costa, P. J.; Felix, V.; Beer,
P. D. J. Amer. Chem. Soc. 2012, 134, 11533ꢀ11541.
(16) Walter, S. M.; Kniep, F.; Herdtweck, E.; Huber, S. M. Angew. Chem. Int. Ed. 2011, 50,
7187ꢀ7191.
(17) Dordonne, S.; Crousse, B.; BonnetꢀDelpon, D.; Legros, J. Chem. Commun. 2011, 47, 5855
–5857.
(18) Wilcken, R.; Zimmermann, M. O.; Lange, A.; Joerger, A. C.; Boeckler, F. M. J. Med.
Chem. 2012, 56, 1363−1388.
(19) Xu, Z.; Yang, Z.; Liu, Y.; Lu, Y.; Chen, K.; Zhu, W. J. Chem. Inf. Model. 2014, 54, 69ꢀ
78.
(20) Marsh, E. N. G. Acc. Chem. Res. 2014, 47, 2878ꢀ2886.
ACS Paragon Plus Environment
22

Page 23 of 28
Crystal Growth & Design
1
2
3
4
5
6
(21) Pauling, L. C. The Nature of the Chemical Bond; Cornell University, New York, 1960.
7
8
9
(22) Reichenbächer, K.; Süss, H. I.; Hulliger, J. Chem. Soc. Rev. 2005, 34, 22ꢀ30.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(23) Okamoto, T.; Nakahara, K.; Saeki, A.; Seki, S.; Oh, J. H.; Akkerman, H. B.; Bao, Z.;
Matsuo, Y. Chem. Mater. 2011, 23, 1646–1649.
(24) Jiang, H.; Ye, J.; Hu, P.; Wei, F.; Du, K.; Wang, N.; Ba, T.; Feng S.; Kloc, C. Sci. Rep.
2014, 4, 7573.
(25) Salini, P. S.; Derry Holaday, M. G.; Reddy, M. L. P.; Suresh C. H.; Srinivasan, A. Chem.
Commun. 2013, 49, 2213ꢀ2215.
(26) Koda, Y.; Terashima, T.; Takenaka, M.; Sawamoto, M. ACS Macro Lett. 2015, 4, 377ꢀ
380.
(27) Liu, L.; Yang, G.; Geng, Y.; Wu, Y.; Su, Z. RSC Adv. 2014, 4, 50188ꢀ50194.
(28) Y. Sakamoto, T. Suzuki, M. Kobayashi, Y. Gao, Y. Fukai, Y. Inoue, F. Sato and S.
Tokito, J. Am. Chem. Soc. 2004, 126, 8138–8140.
(29) S. Ando, R. Murakami, J.ꢀI. Nishida, H. Tada, Y. Inoue, S. Tokito and Y. Yamashita, J.
Am. Chem. Soc. 2005, 127, 14996–14997.
(30) A. Fukazawa, D. Kishi, Y. Tanaka, S. Seki and S. Yamaguchi, Angew. Chem., Int. Ed.
2013, 52, 12091–12095.
(31) Seidel, F. O.; Gladysz, J. A. Adv. Synth. Catal. 2008, 350, 2443ꢀ2449.
ACS Paragon Plus Environment
23

Crystal Growth & Design
Page 24 of 28
1
2
3
4
5
6
(32) Cormanich, R. A.; Rittner, R.; O’Hagan, D.; Bühl, M. J. Phys. Chem. A 2014, 118, 7901ꢀ
7
8
7910.
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(33) Baker, R. J.; Colavita, P.E.; Murphy, D. M.; Platts, J. A.; Wallis, J. D. J. Phys. Chem. A
2012, 116, 1435ꢀ1444.
(34) Thakur, T. S.; Kirchner, M. T.; Blaser, D.; Boese, R; Desiraju, G. CrystEngCom 2010, 12,
2079ꢀ2085.
(35) Shukla, R; Chopra, D. CrystEngComm. 2015, DOI:10.1039/c4ce02391a.
(36) Kaur, G.; Choudhury, A. R. CrystEngComm. 2015, 17, 2949ꢀ2963.
(37) Eskandari, K.; Lesani, M. Chem. Eur. J. 2015, 21, 4739ꢀ4746.
(38) Dalvit, C.; Invernizzi, C.; Vulpetti, A. Chem. Eur. J. 2014, 20, 11058ꢀ11068.
(39) Chopra, D. Cryst. Growth Des. 2012, 12, 541ꢀ546.
(40) Schneider, H.ꢀJ. Chem. Sci. 2012, 3, 1381ꢀ1394.
(41) Schulze B.; Schubert, U. S. Chem. Soc. Rev. 2014, 43, 2522ꢀ2571.
(42) Lu, B.ꢀY.; Li, Z.ꢀM.; Zhu, Y.ꢀY.; Zhao, X.; Li, Z.ꢀT. Tetrahedron 2012, 68, 8857ꢀ8862.
(43) Achilefu, S.; Mansuy, L.; Selve, C.; Thiebaut, S. J. Fluorine Chem. 1995, 70, 19ꢀ26.
(44) Van der Waals radii taken from Alvarez, S. Dalton Trans. 2013, 42, 8617ꢀ8636.
(45) Zimmermann, F.; Meux, E.; Mieloszynski, J.ꢀL.; Lecuireb, J.ꢀM.; Oget, N. Tetrahedron
ACS Paragon Plus Environment
24

Page 25 of 28
Crystal Growth & Design
1
2
3
4
5
6
7
Lett. 2005, 46, 3201–3203.
8
9
(46) As determined by a search in April 2015.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(47) Fournier, J. A.; Bohn, R. K.; Montgomery, Jr., J. A.; Onda, M. J. Phys. Chem. A 2010,
114, 1118–1122.
(48) Consorti, C. S.; Hampel, F.; Gladysz, J. A. Inorg. Chim. Acta 2006, 359, 4874–4884.
(49) Monde, K.; Miura, N.; Hashimoto, M.; Taniguchi, T.; Inabe, T. J. Am. Chem. Soc. 2006,
128, 6000ꢀ6001.
(50) Casnati, A.; Liantonio, R.; Metrangolo, P.; Resnati, G.; Ungaro, R.; Ugozzoli, F. Angew.
Chem., Int. Ed. 2006, 45, 1915ꢀ1918.
(51) Dunitz, J. D.; Gavezzotti, A.; Schweizer, W. B. Helv. Chim. Acta 2003, 86, 4073ꢀ4092.
(52) Watkins, E. K.; Jorgensen, W. L.; J. Phys. Chem. A 2001, 105, 4118ꢀ4125.
(53) Neumann, F.; Teramae, H.; Downing, J. W.; Michl, J. J. Am. Chem. Soc. 1998, 120, 573ꢀ
582.
(54) Albinsson, B.; Michl, J. J. Phys. Chem. 1996, 100, 3418ꢀ3429.
(55) Shapiro, N.; Kramer, M.; Goldberg, I.; Vigalok, A. Green Chem. 2010, 12, 582–584.
(56) Hawthorne, B.; FanꢀHagenstein, H.; Wood, E.; Smith, J.; Hanks T.; Int J
Spectrosc. 2013, 216518.
ACS Paragon Plus Environment
25

Crystal Growth & Design
Page 26 of 28
1
2
3
4
5
6
(57) Nivet, J. B.; Bernelin, R.; Le Blanc, M.; Riess, J. G. Eur. J. Med. Chem. 1992, 27, 891ꢀ
7
8
898.
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(58) Brace, N. O. J. Fluorine Chem. 1986, 31, 151ꢀ174.
(59) Kornblum, N.; Blackwood, R. K. J. Amer. Chem Soc. 1955, 78, 4037ꢀ4039.
(60) Wu, Y.ꢀM.; Deng, J.; Fang, X.; Chen, Q.ꢀY. J. Fluorine Chem. 2004, 125, 1415ꢀ1423.
(61) Wu, Y.ꢀM.; Deng, J.; Li, Y.; Chen, Q.ꢀY. Synthesis 2005, 1314ꢀ1318.
(62) Robbins, A. J.; Ng, W. T. K.; Jochym, D.; Keal, T. W.; Clark, S. J.; Tozer, D. J.;
Hodgkinson, P. Phys. Chem. Chem. Phys. 2007, 9, 2389ꢀ2396.
(63) PérezꢀTorralba, M.; García, M. Á.; López, C.; Torralba, M. C.; Torres, M. R.; Claramunt,
R. M.; Elguero, J. Cryst. Growth Des. 2014, 14, 3499−3509.
(64) NMR Crystallography; Harris, R. K., Wasylischen, R. E., Duer, M. J., Eds.; Wiley:
Chichester, 2009.
(65) YahiaꢀOuahmed, M.; Tognetti, V.; Joubert, L. Comp. Theor. Chem. 2015, 1053, 254ꢀ262
(66) Mercury 3.3, CCDC, http://www.ccdc.cam.ac.uk/mercury/
(67) Waller, M.P; Robertazzi, A.; Platts, J. A.; Hibbs, D.E.; Williams, P.A.; J. Comput. Chem.
2006, 27, 491.
(68) SHELXTL 6.14 Bruker AXS Inc., Madison, WI, 2000ꢀ2003; Sheldrick, G.M. Acta Cryst.
2008, A64, 112ꢀ122.
ACS Paragon Plus Environment
26

Page 27 of 28
Crystal Growth & Design
1
2
3
4
5
6
7
8
(69) Gaussian 09, Revision C.01, M. J. Frisch, G. W. Trucks, H. B. Schlegel, G. E. Scuseria,
M. A. Robb, J. R. Cheeseman, G. Scalmani, V. Barone, B. Mennucci, G. A. Petersson, H.
Nakatsuji, M. Caricato, X. Li, H. P. Hratchian, A. F. Izmaylov, J. Bloino, G. Zheng, J. L.
Sonnenberg, M. Hada, M. Ehara, K. Toyota, R. Fukuda, J. Hasegawa, M. Ishida, T. Nakajima,
Y. Honda, O. Kitao, H. Nakai, T. Vreven, J. A. Montgomery, Jr., J. E. Peralta, F. Ogliaro, M.
Bearpark, J. J. Heyd, E. Brothers, K. N. Kudin, V. N. Staroverov, T. Keith, R. Kobayashi, J.
Normand, K. Raghavachari, A. Rendell, J. C. Burant, S. S. Iyengar, J. Tomasi, M. Cossi, N.
Rega, J. M. Millam, M. Klene, J. E. Knox, J. B. Cross, V. Bakken, C. Adamo, J. Jaramillo, R.
Gomperts, R. E. Stratmann, O. Yazyev, A. J. Austin, R. Cammi, C. Pomelli, J. W. Ochterski, R.
L. Martin, K. Morokuma, V. G. Zakrzewski, G. A. Voth, P. Salvador, J. J. Dannenberg, S.
Dapprich, A. D. Daniels, O. Farkas, J. B. Foresman, J. V. Ortiz, J. Cioslowski, and D. J. Fox,
Gaussian, Inc., Wallingford CT, 2010.
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(70) Grimme, S. J. Comp. Chem. 2006, 27, 1787.
(71) Weigend, F.; Ahlrichs, R. Phys. Chem. Chem. Phys. 2005, 7, 3297ꢀ3305.
(72) Boys, S. F. Bernardi, F. Mol. Phys. 1970, 19, 553.
(73) AIMAll (Version 12.06.03), Todd A. Keith, TK Gristmill Software, Overland Park KS,
USA, 2012.
(74) Marchione, A. A.; Buck R. C. Magn. Reson. Chem. 2009, 47, 194–198.
ACS Paragon Plus Environment
27

Crystal Growth & Design
Page 28 of 28
1
2
3
4
5
6
For TOC only
7
8
9
Further Evidence on the Importance of FluorousꢀFluorous Interactions in Supramolecular
Chemistry: A Combined Structural and Computational Study
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Harrison Omorodion, Brendan Twamley, James A. Platts and Robert J. Baker*
Synopsis: The crystal structures of two compounds featuring a CF3(CF2)5CH2CH2 fluorous
ponytail shows a number of stabilizing C—F...F—C interactions that have also been
characterized by computational methods.
ACS Paragon Plus Environment
28