Crystal structures of seven molecular salts derived from benzylamine and organic acidic components

Article abstract of DOI:10.1016/j.molstruc.2017.03.011

Cocrystallization of the commonly available organic amine, benzylamine, with a series of organic acids gave a total of seven molecular salts with the compositions: (benzylamine): (p-toluenesulfonic acid) (1) [(HL)⁺ · (tsa^?)], (benzylamine): (o-nitrobenzoic acid) (2) [(HL⁺) · (onba)^?], (benzylamine): (3,4-methylenedioxybenzoic acid) (3) [(HL⁺) · (mdba^?)], (benzylamine): (mandelic acid) (4) [(HL⁺) · (mda^?)], (benzylamine): (5-bromosalicylic acid)₂ (5) [(HL⁺) · (bsac^?) · (Hbsac)], (benzylamine): (m-phthalic acid) (6) [(HL⁺) · (Hmpta^?)], and (benzylamine)₂: (trimesic acid) (7) [(HL⁺)₂ · (Htma^2?)]. The seven salts have been characterised by X-ray diffraction technique, IR, and elemental analysis, and the melting points of all the salts were also reported. And their structural and supramolecular aspects are fully analyzed. The result reveals that among the seven investigated crystals the NH₂ groups in the benzylamine moieties are protonated when the organic acids are deprotonated, and the crystal packing is interpreted in terms of the strong charge-assisted N[sbnd]H?O hydrogen bond formation between the ammonium and the deprotonated acidic groups. Except the N[sbnd]H?O hydrogen bond, the O[sbnd]H?O hydrogen bonds (charge assisted or neutral) were also found at the salts 4–7. Further analysis of the crystal packing of the salts indicated that a different family of additional CH[sbnd]O/CH₂[sbnd]O, CH[sbnd]π/CH₂[sbnd]π, O[sbnd]O, and O[sbnd]C_π associations contribute to the stabilization and expansion of the total high-dimensional (2D-3D) framework structures. For the coexistence of the various weak nonbonding interactions these structures adopted homo or hetero supramolecular synthons or both. Some classical supramolecular synthons, such as R₄²(8), R₄³(10) and R₄⁴(12), usually observed in organic solids of organic acids with amine, were again shown to be involved in constructing most of these hydrogen bonding networks.

Full text of DOI:10.1016/j.molstruc.2017.03.011

Accepted Manuscript
Crystal structures of seven molecular salts derived from benzylamine and organic
acidic components
Xianhong Wen, Xiunan Jin, Chengcai Lv, Shouwen Jin, Xiuqing Zheng, Bin Liu, Daqi
Wang, Ming Guo, Weiqiang Xu
PII:
S0022-2860(17)30272-7
10.1016/j.molstruc.2017.03.011
MOLSTR 23507
DOI:
Reference:
To appear in: Journal of Molecular Structure
Received Date: 10 February 2016
Revised Date: 1 March 2017
Accepted Date: 1 March 2017
Please cite this article as: X. Wen, X. Jin, C. Lv, S. Jin, X. Zheng, B. Liu, D. Wang, M. Guo, W. Xu,
Crystal structures of seven molecular salts derived from benzylamine and organic acidic components,
Journal of Molecular Structure (2017), doi: 10.1016/j.molstruc.2017.03.011.
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ACCEPTED MANUSCRIPT
Crystal Structures of Seven Molecular Salts Derived from Benzylamine and
Organic Acidic Components
b
a
a,b
a,b
a,b
Xianhong Wen , Xiunan Jin , Chengcai Lv , Shouwen Jin *, Xiuqing Zheng , Bin
a,b
c
b
a,b
Liu , Daqi Wang , Ming Guo , and Weiqiang Xu
a
JiYang College ZheJiang A & F University, Zhu'Ji 311800, P. R. China, Tel & fax:
+86-575-8776-0141. *E-mail: jinsw@zafu.edu.cn
b
Key Laboratory of Chemical Utilization of Forestry Biomass of Zhejiang Province
Zhejiang A & F University, Lin’an, Zhejiang Province, 311300, China
c
Department of Chemistry, Liaocheng University, Liaocheng 252059, P. R. China.
Abstract:
Cocrystallization of the commonly available organic amine, benzylamine, with a
series of organic acids gave a total of seven molecular salts with the compositions:
+
-
(
(
(
benzylamine) : (p-toluenesulfonic acid) (1) [(HL) · (tsa )], (benzylamine) :
+
-
o-nitrobenzoic
acid)
(2)
[(HL )
·
(onba) ],
(benzylamine)
:
+
-
3,4-methylenedioxybenzoic acid) (3) [(HL ) · (mdba )], (benzylamine) : (mandelic
+
-
acid) (4) [(HL ) · (mda )], (benzylamine) : (5-bromosalicylic acid) (5)
2
+
-
+
-
[
(HL ) · (bsac ) · (Hbsac)], (benzylamine) : (m-phthalic acid) (6) [(HL ) · (Hmpta )],
+
2-
and (benzylamine) : (trimesic acid) (7) [(HL ) · (Htma )]. The seven salts have been
2
2
characterised by X-ray diffraction technique, IR, and elemental analysis, and the
melting points of all the salts were also reported. And their structural and
supramolecular aspects are fully analyzed.
The result reveals that among the seven investigated crystals the NH groups in
2
the benzylamine moieties are protonated when the organic acids are deprotonated, and
the crystal packing is interpreted in terms of the strong charge-assisted N-HꢀO
hydrogen bond formation between the ammonium and the deprotonated acidic groups.
Except the N-HꢀO hydrogen bond, the O-H···O hydrogen bonds (charge assisted or
neutral) were also found at the salts 4-7.

ACCEPTED MANUSCRIPT
Further analysis of the crystal packing of the salts indicated that a different family
of additional CH-O/CH -O, CH-π/CH -π, O-O, and O-C associations contribute to
2
2
π
the stabilization and expansion of the total high-dimensional (2D-3D) framework
structures. For the coexistence of the various weak nonbonding interactions these
structures adopted homo or hetero supramolecular synthons or both. Some classical
2
3
4
4
4
supramolecular synthons, such as R (8), R (10) and R (12), usually observed in
4
organic solids of organic acids with amine, were again shown to be involved in
constructing most of these hydrogen bonding networks.
Keywords: Crystal structures; Nonbonding interactions; Benzylamine; Acidic
components; Organic salts.
Introduction
Noncovalent interactions such as electrostatic forces, hydrogen bonding, CH-π,
π-π stacking, cation-π, anion-π, and lone pair-π hydrogen bonding, as well as other
weak forces play significant roles in various fields ranging from molecular
recognition, host-guest chemistry, crystal engineering, supramolecular chemistry,
biochemistry, pharmaceutical chemistry, to materials science [1-4]. In the past few
years, great efforts have been made to elucidate these interactions and their
relationship to the final supramolecular structures [5]. Besides the noncovalent
interactions, the supramolecular synthons are structural units within organic solids
produced by these intermolecular interactions. And there existed two distinct
categories of supramolecular synthons i.e. supramolecular homo- and heterosynthons,
which was very important for the chemist to understand the synthons at the organic
salt/cocrystal.
In the case of pharmaceutical ingredients, solid organic salts with such
biopharmaceutical properties as solubility, stability and hygroscopicity have been
studied systematically, and these properties are relevant to the noncovalent
interactions [6-7]. The organic acids with the nice donor-acceptor groups are good
blocks for the multi-component assembly [8], and they aggregate in the solid state as

ACCEPTED MANUSCRIPT
dimer, catemer, and bridged motifs [9], so they are frequently chosen as building
blocks in the supramolecular crystal engineering.
A myriad of acid-base mediated supramolecular assemblies were explored
through the powerful and directional recognition behavior between the organic acids
and the basic components such as aromatic amine, aliphatic amine and pyridyl
derivatives [10]. Amongst, a notable such studies were often directed towards
systematic analysis on a kind of homologues series by varying the basic components
for a given acid [11]. In order to create high-dimensional assemblies and elucidate
molecular crystals especially the synthons between the benzylamine and the organic
acids, we select some organic acids possessing methyl, nitro, halogen, OH and
aromatic moieties which are all excellent groups in forming the organic crystalline
solids through a wide variety of non-covalent interactions [12]. As an amine
derivative, except the basic NH group, benzylamine has the additional rigid phenyl
2
ring and the somewhat flexible CH linker, which can provide more complex
2
noncovalent associations when it associated with the organic acids. To the best of our
knowledge there are few reports dealing with the organic acid-base adducts
concerning the Lewis base of benzylamine [13, 14].
Recently, we have focused our continuing efforts on the systematic study of
hydrogen bonding, π-π interaction, and halogen bonding concerning the given
N-containing derivatives with varying the organic acids [15], we will report herein the
preparation and structures of seven organic salts assembled from benzylamine (L) and
the corresponding organic acids ranging from mono-acid to tri-acid (Scheme 1),
respectively. The seven organic salts are (benzylamine) : (p-toluenesulfonic acid) (1)
+
-
+
-
[
(
(
(
(HL) · (tsa )], (benzylamine) : (o-nitrobenzoic acid) (2) [(HL ) · (onba) ],
+
-
benzylamine) : (3,4-methylenedioxybenzoic acid) (3) [(HL ) · (mdba )],
+
-
benzylamine) : (mandelic acid) (4) [(HL ) · (mda )], (benzylamine) :
+
-
5-bromosalicylic acid) (5) [(HL ) · (bsac ) · (Hbsac)], (benzylamine) : (m-phthalic
2
+
-
acid) (6) [(HL ) · (Hmpta )], and (benzylamine) : (trimesic acid) (7)
2
+
2-
[
(HL ) · (Htma )] (Scheme 2). The supramolecular synthons of the salts 1-7 were
2
listed at Scheme 3.

ACCEPTED MANUSCRIPT
O N
2
O
H N
2
O
S
OH
O
HO
benzylamine
p-toluenesulfonic acid
o-nitrobenzoic acid
HO
O
O
O
OH
O
O
HO
OH
HO
Br
5-bromosalicylic acid
3
,4-methylenedioxybenzoic acid
mandelic acid
O
OH
HO
O
HO
OH
O
O
O
HO
trimesic acid
m-phthalic acid
Scheme 1 Molecular structures of the components present in salts 1-7.

ACCEPTED MANUSCRIPT
Scheme 2 The seven organic salts described in this paper, 1-7.

ACCEPTED MANUSCRIPT
O
S
O
O
O
O
H
S
H
H
O
H
H
O
O
S
O
N
H
N
H
O
H
H
H
N
H
H
H
H
N
H
O
S
O
I
II
III
2
O N
O
2
N
H
O
O
O
H
H
O
2
O N
H
N
N
H
N
H
O
H
H
O
H
H
N
H
O
H
O
H
O
H
N
O
NO
2
H
NO
2
VI
IV
V
O
O
O
O
O
O
H
N
H
O
H
H
N
O
H
H
O
H
O
H
O
H
O
O
O
O
O
O
H
H
H
O
H
N
O
H
O
IX
VII
VIII
HO
H
O
H
O
N
H
H
H
N
H
O
H
N
O
H
H
O
O
H
O
H
O
O
O
H
O
O
OH
OH
XI
X
XII
HO
O
O
H
N
H
H
N
H
H
O
H
O
OH
XIII

ACCEPTED MANUSCRIPT
Br
H
O
H
O
N
H
HO
Br
H
HO
Br
H
O
H
O
O
O
H
O
H
O
H
O
OH
O
H
OH
O
Br
Br
XIV
XVI
XV
Br
H
H
N
H
H
H
N
H
H
HO
H
H
O
O
H
H
O
O
O
H
O
O
H
O
H
O
O
O
H
O
O
OH
H
N
H
Br
Br
Br
XIX
XVII
XVIII
H
N
H
H
O
O
O
H
H
O
H
O
H
O
O
H
H
O
O
O
O
O
O H
O
H
O
H
O
H
O
H
H
N
O
H
H
O
H
N
O
H
H
XXII
XX
XXI
H
H
H
H
O
H
H
O
N
N
H
N
O
O H
H
O
O
H
H
H
H
O
O
O
O H
H
O
O
H
O
O
O
O
O
O
O
O
O
O
O
O
XXIII
XXIV
XXV
O
O
O
O
H
H
H
H
N
N
O
O
O
O
O
H
H
H
O
O
H
O
H
H
H
H
O
O H
O
O H
H
H
H
O
O
O
O
N
N
H
H
H
O
O
O
O
XXVI
XXVII
Scheme 3 Supramolecular synthons of salts 1-7.
Experimental section
Materials and Physical Measurements

ACCEPTED MANUSCRIPT
The chemicals and solvents used in this work were of analytical grade
commercial products and were used without further purification. The FT-IR spectra
-1
were recorded from KBr pellets in range 4000-400 cm on a Mattson Alpha-Centauri
spectrometer, and the IR bands were marked as strong (s), medium (m), and weak (w)
at the preparation part. The asymmetrical and symmetrical IR vibration bands of the
corresponding groups were shown as ν and ν , respectively. The carbon, hydrogen,
as
s
nitrogen, and sulfur data were obtained microanalytically on a Perkin-Elmer
elemental analyzer (with Model 2400II). The melting points of the new compounds
were measured by an XT-4 thermal apparatus without correction.
Preparation of the salts 1-7
+
-
a. (benzylamine) : (p-toluenesulfonic acid) [(HL) · (tsa )] (1)
To a methanol solution (8 mL) of p-toluenesulfonic acid monohydrate (38 mg,
0
.2 mmol), benzylamine (21.4 mg, 0.2 mmol) was added. The solution was stirred for
a few minutes, then the solution was filtered into a test tube. The solution was left
standing at room temperature for several days, colorless crystals were isolated after
slow evaporation of the methanol solution in air. The crystals were collected and dried
+
-
in air to give the title compound [(HL) · (tsa )] (1). Yield: 46 mg, 82.33% (based on
benzylamine L). m. p. 76-78 °C. Anal. Calcd for C H NO S (279.35): C, 60.14; H,
14
17
3
6
.08; N, 5.01; S, 11.46. Found: C, 60.08; H, 6.03; N, 4.97; S, 11.42. Infrared spectrum
-1
(
KBr disc, cm ): 3446s(ν (NH)), 3368s(ν (NH)), 3230m, 3139m, 3045m, 2962m,
as s
2
1
8
870m, 2825m, 2770m, 2729m, 1628m, 1589m, 1547m, 1505m, 1462m, 1417m,
374m, 1333m, 1279m, 1236m, 1188m, 1145m, 1099m, 1051m, 1008m, 969m, 920m,
79m, 832m, 789m, 742m, 700m, 666m, 630m, 605m.
+
-
b. (benzylamine) : (o-nitrobenzoic acid) [(HL ) · (onba) ] (2)
To a methanol solution (5 mL) of o-nitrobenzoic acid (33.4 mg, 0.2 mmol),
benzylamine (21.4 mg, 0.2 mmol) was added. The solution was stirred for a few
minutes, then the solution was filtered into a test tube. Colorless block crystals were
isolated after two weeks from the solution at room temperature in air. The crystals

ACCEPTED MANUSCRIPT
+
-
were collected and dried in air to give the title compound [(HL ) · (onba) ] (2). Yield:
4
5
6 mg, 83.86%. m. p. 146-147°C. Anal. Calcd for C H N O (274.27): C, 61.25; H,
14 14 2 4
.10; N, 10.21. Found: C, 61.22; H, 5.04; N, 10.17. Infrared spectrum (KBr disc,
-1
cm ): 3411m(ν (NH)), 3326w(ν (NH)), 3214m, 3015m, 2976m, 2928w, 2824w,
as
s
-
2
1
1
6
724w, 2630m, 2420m, 1627m, 1585s(ν (COO )), 1544m, 1515s(ν (NO )), 1472m,
as as 2
-
438m, 1395s(ν (COO )), 1355m, 1315s(ν (NO )), 1272m, 1229m, 1187m, 1141m,
s
s
2
100m, 1055m, 1012m, 971m, 928m, 882m, 840m, 797m, 755m, 712m, 670m, 635m,
10m.
+
-
c. (benzylamine) : (3,4-methylenedioxybenzoic acid) [(HL ) · (mdba )] (3)
To a methanol solution (10 mL) of 3,4-methylenedioxybenzoic acid (33.2 mg, 0.2
mmol), benzylamine (21.4 mg, 0.2 mmol) was added. The solution was stirred for a
few minutes, then the solution was filtered into a test tube. Colorless block crystals
were isolated after several weeks from the solution at room temperature in air. The
+
-
crystals were collected and dried in air to give the title compound [(HL ) · (mdba )]
(
3). Yield: 38 mg, 69.52% (based on L). m. p. 189-191°C. Anal. Calcd for C H NO
15 15 4
(273.28): C, 65.87; H, 5.49; N, 5.12. Found: C, 65.82; H, 5.44; N, 5.07. Infrared
-1
spectrum (KBr disc, cm ): 3412m(ν (NH)), 3327w(ν (NH)), 3240m, 3164m, 2926m,
as
s
-
2
1
1
844w, 2785w, 2670w, 2631w, 1611s(ν (COO )), 1566m, 1523m, 1480m, 1439m,
as
-
397s(ν (COO )), 1356m, 1313m, 1271m, 1228m, 1186m, 1142m, 1098m, 1056m,
s
012m, 968m, 923m, 882m, 839m, 795m, 749m, 706m, 663m, 624m.
+
-
d. (benzylamine) : (mandelic acid) [(HL ) · (mda )] (4)
To a methanol solution (10 mL) of mandelic acid (33.2 mg, 0.2 mmol),
benzylamine (21.4 mg, 0.2 mmol) was added. The solution was stirred for a few
minutes, then the solution was filtered into a test tube. Colorless block crystals were
isolated after several weeks from the solution at room temperature in air. The crystals
+
-
were collected and dried in air to give the title compound [(HL ) · (mda )] (4). Yield:
3
6
5 mg, 67.49% (based on L). m. p. 83-85°C. Anal. Calcd for C H NO (259.30): C,
15 17 3
9.42; H, 6.56; N, 5.40. Found: C, 69.38; H, 6.51; N, 5.35. Infrared spectrum (KBr

ACCEPTED MANUSCRIPT
-1
disc, cm ): 3688w(ν(HO), 3440m(ν (NH)), 3367w(ν (NH)), 3271m, 3162m, 2991m,
as
s
-
2
1
1
844w, 2783w, 2671w, 2625w, 1620s(ν (COO )), 1578m, 1533m, 1491m, 1450m,
as
-
406s(ν (COO )), 1364m, 1320m, 1276m, 1233m, 1189m, 1145m, 1099m, 1057m,
s
016m, 970m, 927m, 884m, 843m, 800m, 757m, 714m, 672m, 631m, 604m.
+
-
e. (benzylamine) : (5-bromosalicylic acid) [(HL ) · (bsac ) · (Hbsac)] (5)
2
To a methanol solution (10 mL) of 5-bromosalicylic acid (43.4 mg, 0.2 mmol),
benzylamine (21.4 mg, 0.2 mmol) was added. The solution was stirred for a few
minutes, then the solution was filtered into a test tube. Colorless block crystals were
isolated after several weeks from the solution at room temperature in air. The crystals
+
-
were collected and dried in air to give the title compound [(HL ) · (bsac ) · (Hbsac)]
5). Yield: 78 mg, 72.06% (based on L). m. p. 141-142°C. Anal. Calcd for
C H Br NO (541.19): C, 46.56; H, 3.51; N, 2.59. Found: C, 46.50; H, 3.44; N, 2.55.
(
21
19
2
6
-1
Infrared spectrum (KBr disc, cm ): 3702w(ν(HO), 3440m(ν (NH)), 3380w(ν (NH)),
as
s
-
3
1
1
264m, 3149m, 2988m, 2846w, 2784w, 1597s(ν (COO )), 1554m, 1515m, 1474m,
as
-
433m, 1391s(ν (COO )), 1346m, 1304m, 1263m, 1220m,, 1179m, 1136m, 1094m,
s
053m, 1009m, 965m, 917m, 875m, 833m, 787m, 746m, 700m, 656m, 621m, 600m.
+
-
f. (benzylamine) : (m-phthalic acid) [(HL ) · (Hmpta )] (6)
To a methanol solution (10 mL) of m-phthalic acid (33.2 mg, 0.2 mmol),
benzylamine (21.4 mg, 0.2 mmol) was added. The solution was stirred for a few
minutes, then the solution was filtered into a test tube. Colorless block crystals were
isolated after several weeks from the solution at room temperature in air. The crystals
+
-
were collected and dried in air to give the title compound [(HL ) · (mpta )] (6). Yield:
4
6 mg, 84.16% (based on L). m. p. 241-242°C. Anal. Calcd for C H NO (273.28):
1
5
15
4
C, 65.87; H, 5.49; N, 5.12. Found: C, 65.84; H, 5.469; N, 5.09. Infrared spectrum
-1
(
KBr disc, cm ): 3655w(br, ν(HO), 3431m(ν (NH)), 3333w(ν (NH)), 3245m, 3166m,
as s
-
2
990m, 2844w, 2785w, 1656s(ν(C=O)), 1609s(ν (COO )), 1563m, 1520m, 1478m,
as
-
1
437m, 1405s(ν (COO )), 1361m, 1295s(ν(C-O)), 1253m, 1212m, 1169m, 1127m,
s

ACCEPTED MANUSCRIPT
1
6
085m, 1039m, 996m, 957m, 914m, 872m, 828m, 788m, 746m, 704m, 660m, 619m,
04m.
+
2-
g. (benzylamine) : (trimesic acid) [(HL ) · (Htma )] (7)
2
2
To a methanol solution (10 mL) of trimesic acid (42 mg, 0.2 mmol), benzylamine
21.4 mg, 0.2 mmol) was added. The solution was stirred for a few minutes, then the
(
solution was filtered into a test tube. Colorless block crystals were isolated after
several weeks from the solution at room temperature in air. The crystals were
+
2-
collected and dried in air to give the title compound [(HL ) · (Htma )] (7). Yield: 34
2
mg, 80.10% (based on L). m. p. 253-254°C. Anal. Calcd for C H N O (424.44): C,
2
3
24
2
6
6
5.03; H, 5.65; N, 6.60. Found: C, 64.97; H, 5.62; N, 6.57. Infrared spectrum (KBr
-1
disc, cm ): 3644w(br, ν(HO), 3451m(ν (NH)), 3347w(ν (NH)), 3260m, 3143m,
as
s
-
2
1
1
6
982m, 2824w, 2781w, 1643s(ν(C=O)), 1599s(ν (COO )), 1556m, 1413m, 1471m,
as
-
430m, 1388s(ν (COO )), 1346m, 1302s(ν(C-O)), 1259m, 1217m, 1174m, 1133m,
s
091m, 1048m, 1004m, 961m, 919m, 877m, 834m, 792m, 745m, 703m, 662m, 631m,
11m.
X-ray Crystallography and Data Collection
Single-crystal X-ray diffraction studies for the seven compounds were carried out
via a Bruker SMART 1000 CCD diffractometer operating at 50 kV and 40 mA using
Mo Kα radiation (λ = 0.71073 Å, monochromator graphite). Data collection and
reduction were completed using the SMART and SAINT softwares [16]. The
structures were solved by direct methods, and the non-hydrogen atoms were subjected
2
to anisotropic refinement by full-matrix least squares on F using SHELXTL package
[
17].
All H atoms were placed in geometrically calculated positions and included in the
refinement in a riding-model approximation. Data collection and structure refinement
parameters along with crystallographic data for all compounds are given in Table 1
and Table 2, while selected bond lengths, bond angles, and hydrogen bond geometries
are listed in Tables 3, and 4.

ACCEPTED MANUSCRIPT
Table 1. should be inserted here.
Table 2. should be inserted here.
Results and Discussion
Preparation and General Characterization
All salts 1-7 were prepared by the same method of mixing the acids with the
benzylamine with 1:1 ratio in methanol solvents, and the crystals were obtained at
ambient conditions via the common solvent evaporating technique. All compounds
crystallized without water or methanol molecules accompanied, and the seven
crystalline products are not hygroscopic. Fig. 1, Fig. 3, Fig. 5, Fig. 7, Fig. 9, Fig. 11,
and Fig. 13 exhibit the molecular structures and their atom labelling schemes for the
seven structures, respectively.
The O-H or N-H stretching frequencies were found at approximately 3688-3326
-1
cm as strong and broad bands in the IR spectra of the seven compounds. The
-1
-1
medium intensity bands occurred in the regions of 1500-1630 cm and 600-750 cm
are attributed to the aromatic ring stretching and bending, respectively. IR
spectroscopy is very useful for the diagnosis of proton transfer compounds [18], for in
the proton transfer compounds 2-7, the most distinct feature in the IR spectrum are the
-
1
-1
presence of strong asymmetrical (1580-1620 cm ) and symmetrical (1388-1406 cm )
carboxylate stretching frequencies [19], respectively.
Table 3. should be inserted here.
Table 4. should be inserted here.
Structural descriptions
+
-
X-ray structure of (benzylamine) : (p-toluenesulfonic acid) [(HL) · (tsa )] (1)
Fig. 1 should be inserted here.
Fig. 2 should be inserted here.
The analysis of the XRD data indicated the title compound crystallized as triclinic
colorless crystals in the centrosymmetric space group P-1. The compound 1 is a salt
with the SO H groups of the p-toluenesulfonic acids fully donated its H to the NH of
3
2
the benzylamine molecules, which is also verified by the O-S bond lengths

ACCEPTED MANUSCRIPT
(
1.4425(19)-1.4533(18) Å) at the deprotonated SO H. These O-S bond lengths are
3
comparable to those in other documented 4-toluenesulfonate salt [20]. Fig. 1 shows
the asymmetric unit of the compound 1 that contains the benzylaminium cation and
the p-toluenesulfonate anion. The rms (root mean square) deviations of the phenyl
rings of the cation and the anion are 0.0048 Å and 0.0024 Å, respectively, and both
phenyl rings subtended at an angle of 53.9° with each other. The plane composed of
the N group and the CH spacer at the same cation was roughly perpendicular to the
2
phenyl plane that they are attached.
One anion was bonded to one cation via the N-H···O hydrogen bond between the
+
-
NH and one O atom of the SO group with N-O distance of 2.861(3) Å, and CH-π
3
3
association between the phenyl CH of the anion and the phenyl ring of the cation with
C-Cg (Cg is the gravity centre of the phenyl ring of the cation) distance of 3.646 Å to
form a heteroadduct. Two such heteroadducts generate a tetracomponent aggregate by
+
a pair of N-H···O hydrogen bonds between the NH of the cation and the oxygen
3
-
atom of the SO group with N-O distance of 2.884(3) Å, and CH -O association from
3
2
-
the CH spacer of the cation and the SO with C-O separation of 3.177 Å, generating
2
3
1
4
the close joint synthons II R (5), and III R (12). Similar with the documented
2
4
4
ammonium sulfonate salts [21], here the most common III R (12) synthon was also
4
+
produced by two sulfonate O atoms and two H of each NH3 via the bridging
amino-sulfonate hydrogen bonds.
In the tetracomponent aggregate the corresponding cations and anions were
inversionally related with the inversion centre located at the middle point of the two
-
SO groups. The tetracomponent aggregates were linked together to form 1D chain
3
running along the a axis direction with the assistance of two CH-O associations. Of
-
the two CH-O associations one is between the phenyl CH of the anion and the SO3
group with C-O distance of 3.424 Å, and the other exists between the phenyl CH of
-
the cation and the SO group with C-O distance of 3.496 Å. Within the crystal
3
structure, neighboring chains are linked through additional interchain N-H···O
+
-
hydrogen bond between the NH and the oxygen atom of the SO group with N-O
3
3
distance of 2.918(3) Å to give an overall 2D hydrogen bonded network running

ACCEPTED MANUSCRIPT
parallel to the ab plane (Fig. 2). In addition, the crystal lattice is stabilized further
through interchain CH-O association between the phenyl CH of the cation and the
-
-
SO with C-O distance of 3.454 Å, and O-O contact between the O atoms of the SO
3
3
groups with O-O distance of 3.010 Å. It is noteworthy to be pointed out that the O-O
distance in the O-O contact was in accordance with the published value of 2.965(4) Å
1
[
22]. The above interchain N-H···O and CH-O associations produced the I (R (7))
2
synthon.
+
-
X-ray structure of (benzylamine) : (o-nitrobenzoic acid) [(HL ) · (onba) ] (2)
Fig. 3 should be inserted here.
Fig. 4 should be inserted here.
Compound 2 crystallizes as monoclinic colorless crystals in the space group
P2(1)/c with Z =12. Although there was a documented salt of the same formula [14d],
the differences between the two salts were the temperatures that the X-ray analysis
were performed (298(2)/100(2)), and the Z values (12/4). The most important fact was
that the crystal structure of the documented salt was not described in detail, so we
described the structure again in depth. The asymmetric unit of 2 contains three thirds
cation of benzylaminium, and three thirds of o-nitrobenzoate, as depicted in Fig. 3.
From the bond distances of the O(1)-C(22) (1.257(3) Å), O(2)-C(22) (1.248(3) Å),
O(5)-C(29) (1.242(4) Å), O(6)-C(29) (1.251(3) Å), O(9)-C(36) (1.228(4) Å), and
O(10)-C(36) (1.246(4) Å) at the carboxylates (Table 3), it can be decided that the
compound 2 was also an organic salt. The differences (ꢀ are 0.009 Å, 0.009 Å, and
-
0
.018 Å) in bond distances between the pair of O-C bonds in the same COO group in
the compound 2 are in the range of the deprotonated COOH (Table 3). In the salt 2,
+
there were strong electrostatic interactions between the charged units of NH and the
o-nitrobenzoate.
One anion and one cation form a heteroadduct A by the N-H···O hydrogen bond
+
-
between the NH and one O atom of the COO group with N-O distance of 2.764(3)
3
Å. The other anion was associated with the other cation via the bifurcated N-H···O
+
-
hydrogen bonds between the NH and both O atoms of the COO with N-O distances
3

ACCEPTED MANUSCRIPT
2
of 2.715(3)-3.276(4) Å to form a heteroadduct B with the synthon IV (R (4)). The
1
heteroadduct A and B were joined together by the N-H···O hydrogen bonds between
+
the NH3 and the oxygen atoms of the carboxylate with N-O distances of
2
.817(3)-2.819(3) Å, CH-O association between the phenyl CH of the cation and the
O atom of the carboxylate with C-O distance of 3.360 Å, and CH-π association
between the phenyl CH of the cation and the phenyl nucleus of the anion with C-Cg
distance of 3.703 Å to generate a tetracomponent aggregate. The N-H···O hydrogen
2
bonds between heteroadduct A and B formed the V R (8) synthon. Two
4
tetracomponent aggregates were further connected together to produce an
+
eight-component aggregate by the N-H···O hydrogen bond between the NH and the
3
oxygen atoms of the carboxylate with N-O distance of 2.706(4) Å. The third anion
+
was bonded to the third cation by the N-H···O hydrogen bond between the NH and
3
one oxygen atom of the carboxylate with N-O distance of 2.783(3) Å to form a
heteroadduct C. Two heteroadduct C produced a tetracomponent aggregate C by the
+
N-H···O hydrogen bond between the NH and the oxygen atom of the carboxylate
3
4
with N-O distance of 2.761(3) Å exhibiting the VI (R (12)) ring motif. The VI
4
4
(
R (12)) ring motif was also frequently found at other ammonium carboxylate salts
4
+
-
of the general formula (R-NH ) · (R’-CO ) [23].
3
2
Salt 2 exhibited 1-D chain running along the a axis direction based on the
interlinked tetracomponent aggregate C and the eight-component aggregate by the
+
N-H···O hydrogen bonds between the NH and the carboxylate with N-O distances
3
of 2.768(3)-2.819(3) Å. Herein the tetracomponent aggregate C and the
eight-component aggregate alternated along the chain. Furthermore the CH-O
associations between the phenyl CH of the anion, the carboxylate, and the nitro group
with C-O distances of 3.433-3.634 Å, and CH-π association between the phenyl CH
of the anion and the phenyl ring of the cation with C-Cg separation of 3.530 Å
connected the neighboring 1D chains to form 2D corrugated sheet extending at the
direction that made an angle of ca. 60° with the ab plane (Fig. 4). In this regard the
phenyl rings of the anions at two neighboring chains were perpendicular with each
other, so did the phenyl rings of the cations belonging to two neighboring chains. The

ACCEPTED MANUSCRIPT
phenyl rings of the cations at the first chain were parallel to the phenyl rings of the
cations at the third chain, so did the phenyl rings of the anions at the first chain and
the phenyl rings of the anions at the third chain. In the third dimension, the 2D
corrugated sheets were interlinked through CH-O associations between the phenyl CH
of the anion, the carboxylate, and the nitro group with C-O distances of 3.329-3.634 Å
to form the final 3-D network where the neighboring sheets were glided some
distance from each other along the extending directions.
X-ray structure of (benzylamine) : (3,4-methylenedioxybenzoic acid)
+
-
[
(HL ) · (mdba )] (3)
Fig. 5 should be inserted here.
Fig. 6 should be inserted here.
As depicted in Fig. 5, the molecular structure of 3 which belongs to the
monoclinic P2(1)/c space group, crystallizes with one molecule of
3
,4-methylenedioxybenzoic acid which is absolutely deprotonated and one molecule
of protonated benzylamine. The C-O bond lengths in the carboxylate are 1.268(4) Å
O(1)-C(8)) and 1.258(4) Å (O(2)-C(8)) with the ꢀ value of 0.01 Å, supporting the
(
ionization of the COOH at the 3,4-methylenedioxybenzoic acid.
The rms deviation of the rings containing C2-C7 atoms and C9-C14 atoms are
.0040 Å and 0.0033 Å, and the dihedral angle between the both rings is 119.9º. The
0
rms deviation of the 5-membered ring of the 1,3-dioxole is 0.0186 Å, which forms
dihedral angles of 119.4º, and 0.5º with the phenyl rings containing C2-C7 and
C9-C14 atoms, respectively. The carboxylate group twisted out of the phenyl ring
plane with C9-C14 atoms only by 9.0˚, indicating the almost coplanarity of both units.
One cation was bonded to one anion through the strong N-H···O hydrogen bond
+
between the NH and one O atom of the carboxylate with H-O and N-O distances of
3
1
.83 Å and 2.705(4) Å to form a heteroadduct. There also existed weak CH-O
association between the phenyl CH of the cation and the other O of the carboxylate
2
with C-O distance of 3.584 Å, which formed a graph-set motif of VIII (R (9))
2
together with the just mentioned N-H···O hydrogen bond. The heteroadducts extend

ACCEPTED MANUSCRIPT
in the form of infinite chains through the N-H···O hydrogen bonds along the b axis
direction [N(1)-H(1A)···O(1)#3, 2.789(5) Å, 169.2°, #3 -x+1, y-1/2, -z+3/2] formed
+
between the NH and the carboxylate. With the help of the N-H···O hydrogen bond
3
+
between the NH3 cation and the O atom of the carboxylate with N-O distance of
2
.786(4) Å, two 1D chains were joined together to form a double chain. Between the
3
two chains at the double chain there generated the IX (R (10)) ring motif, which was
4
also one of the frequently found supramolecular heterosynthons at the ammonium
carboxylate [24].
The cations belonging to the same chain were parallel to each other, and the
cations belonging to two different chains at the double chain were antiparallel to each
other. The adjacent double chains were bridged together through the additional weak
CH -O associations between the CH of the O-CH -O and the O at the O-CH -O with
2
2
2
2
C-O separation of 3.096 Å to form the extending 2D sheet running at the direction
that made an angle of ca. 60° with the ab plane (Fig. 6). The CH -O associations
2
2
produced the VII (R (6) ring) synthon. In the third dimension, the crystal lattice is
2
propagated further through the independent CH-O association between the phenyl CH
of the cation and the carboxylate with C-O distance of 3.329 Å, giving a complex 3D
layer network structure.
+
-
X-ray structure of (benzylamine) : (mandelic acid) [(HL ) · (mda )] (4)
Fig. 7 should be inserted here.
Fig. 8 should be inserted here.
In the compound 4 the N group in the L molecule was assumed to be protonated
with H atom from the COOH group in mandelic acid, thus 4 was an organic salt also.
In the asymmetric unit of 4 there existed one cation of HL, and one mandelate (Fig. 7),
generating one pair of ion pair. The C-O bond lengths of the carboxylate group
C8-O1-O2 were 1.239(4) Å, and 1.255(3) Å, respectively, with the difference (0.016
Å) between the pair of C-O bonds greatly smaller than the corresponding ꢀ value
found in the crystal of the unionized (RS)-mandelic acid [25]. The rms deviations of
the phenyl rings C2-C3-C4-C5-C6-C7 and C10-C11-C12-C13-C14-C15 are 0.0040 Å,

ACCEPTED MANUSCRIPT
and 0.0055 Å, respectively, in which the two rings inclined at an angle of 51.1° with
each other. The carboxylate O1-O2-C8 underwent an approximate 108.8° rotation
from the phenyl ring plane (C10-C11-C12-C13-C14-C15), which is due to the flexible
-
linker between the COO group and the phenyl ring. The plane defined by the N group
and the CH spacer of the cation lied nearly orthogonal to the phenyl plane to which
2
they are attached.
+
The N-H···O hydrogen bond between the NH3 and one O of the carboxylate
with N-O distance of 2.767(3) Å, and CH-O association between the phenyl CH of the
cation and the other O of the carboxylate with C-O distance of 3.404 Å united one
2
anion and one cation into a bicomponent adduct exhibiting the XI R (9) synthon
2
which was similar with the VIII synthon at the salt 3. Two bicomponent adducts were
+
held together by the N-H···O hydrogen bond between the NH3 and the O of the
carboxylate that was involved in the CH-O association with N-O distance of 2.838(3)
4
Å to form a tetracomponent aggregate with XIII (R (12)) synthon as found at 1-2.
4
Along the a axis direction, the tetracomponent aggregates were linked to each other
+
by the N-H···O hydrogen bond from the NH and the O atom of the carboxylate that
3
had the CH-O association with N-O distance of 2.728(3) Å to form 1D chain along
the a axis direction. In the chain the N-H···O hydrogen bonds between the
2
tetracomponent aggregates found the XII (R (8)) synthon which was the same as the
4
V synthon at 2. Further connection through O-H···O hydrogen bond between the
-
alcohol group and the COO with O-O distance of 2.855(3) Å generates an overall 2D
sheet extending parallel to the ab plane (Fig. 8), in which the neighboring chains were
moved some distance from each other along the a axis direction. Herein the O-H···O
2
hydrogen bonds produced a ring with X (R (10)) synthon.
2
X-ray
structure
of
(benzylamine)
:
(5-bromosalicylic
acid)2
+
-
[
(HL ) · (bsac ) · (Hbsac)] (5)
Fig. 9 should be inserted here.
Fig. 10 should be inserted here.
Crystallization of benzylamine and 5-bromosalicylic acid in a 1:1 ratio from the

ACCEPTED MANUSCRIPT
solvent of methanol gave single crystals suitable for X-ray diffraction. The compound
5
belongs to triclinic block crystals in the space group P-1, in which only the proton at
the COOH was fully transferred to the N atom of the L molecule forming an organic
salt. In an asymmetric unit of 5 there existed entire ions of HL cation,
5
-bromosalicylic acid monoanion, and 5-bromosalicylic acid molecule, as shown in
Fig. 9. Herein the composition of the compound 5 was similar to the published
+
-
compound of [(C H N ) · (C H O Cl) ] · C H O Cl(C H O Cl = 5-chlorosalicylic
3
5
2
7
4
3
7
5
3
7
5
3
acid) [26]. Structural and conformational features like those previously observed are
-
found at the bsac anion in 5 also [26]. The anticipated intramolecular hydrogen bond
is established between the phenol group and a carboxyl O atom (O(3)-H(3)···O(2),
2
.512(7) Å, 147.6º) which has comparable strength as those found in the salt
+
-
[
(C H N ) · (C H O Cl) ] · C H O Cl from the imidazole and the 5-chlorosalicylic
3 5 2 7 4 3 7 5 3
acid [26]. Due to the planarity of the hydrogen bonded carboxylate unit, the O-O
separation is in the range of the archived results [2.489-2.509 Å] [27], but it is slightly
shortened when it is compared with the unproton transfer examples (2.547-2.604 Å,
mean: 2.588 Å). The C-O bond distances of the carboxylate varied from 1.252(9) Å
(O(1)-C(8)) to 1.260(8) Å (O(2)-C(8)) with the ꢀ value of 0.008 Å, lending strong
support to the suggested ionic character of 5. The C-O bond distances of the
O4-C15-O5 were 1.302(10) Å, and 1.215(9) Å with the ꢀ value of 0.087 Å, the
-
significantly difference of the ꢀ values at the COO and COOH groups further verifies
our correct assignment of the H atom at the COOH. The rms deviation of the phenyl
ring with C2-C7 is 0.0044 Å. The rms deviation of the phenyl ring of the anion is
0
.0101 Å. The dihedral angle between the two phenyl ring planes is 80.5°. The rms
deviation of the ring with C16-C21 is 0.0034 Å, this ring subtended at dihedral angles
of 82.3°, and 1.9° with the rings C2-C7 and C16-C21, respectively.
Two anions were held together by the O-H···O hydrogen bond between the
-
phenol unit and the COO with O-O distance of 3.128(7) Å to form an anion dimer. At
the anion dimer there were bonded two 5-bromosalicylic acid molecules by the
-
O-H···O hydrogen bond between the COOH unit and the COO with O-O distance of
2
.599(7) Å, and CH-O association between the phenyl CH of the anion and the OH of

ACCEPTED MANUSCRIPT
the COOH with C-O distance of 3.303 Å to form a tetracomponent adduct. The same
with the salicylic acid derivatives [26, 27], the intramolecular O-H···O hydrogen
1
bonds displaying the S (6) rings were also occurred at both the anion and the
1
5
-bromosalicylic acid molecule. At the tetracomponent adduct there were attached
+
two cations via the N-H···O hydrogen bonds from the NH , the phenol group, and
3
both O atoms of the carboxylate with N-O distances of 2.772(9)-3.156(8) Å, CH-O
association between the phenyl CH of the cation and the carbonyl unit of the COOH
with C-O distance of 3.428 Å, and CH -O association between the CH spacer of the
2
2
cation and the carbonyl unit of the COOH with C-O distance of 3.452 Å to generate a
six-component assembly with an inversion centre located at the middle point of the
two anions.
The six-component assemblies are further mediated by the CH-O association
between the phenyl CH of the 5-bromosalicylic acid and the phenol group of the
5-bromosalicylic acid with C-O distance of 3.506 Å to form 1D chain. The discrete
1D parallel chains formed a sheet extending at the direction that made an angle of ca.
60° with the bc plane (Fig. 10), but there were not found any bonding interactions
2
1
2
2
between these chains. At the chain the synthons XIV R (8), XIX R (6), XV R (7),
2
2
2
2
3
XVI R (4), XVII R (6), and XVIII R (9) were found. Different from 1, 2, and 4,
1
3
3
4
2
+
-
there were neither R (12) nor R (8) synthons produced by the NH ··· OOC at 5,
4
4
3
which may be caused by the presence of the phenol units participating in multiple
-
+
O-H···O hydrogen bond which blocked the COO from bridging the NH . Within the
3
crystal structure, neighboring sheets are linked through additional intersheet N-H···O
+
hydrogen bonds between the NH3 and the carboxylate with N-O distances of
2
.907(8)-3.245(8) Å to give an overall 3D hydrogen bonded network. In this case the
discrete chains belonging to two neighboring sheets were slide some distance from
each other along the running direction of the chain.
+
-
X-ray structure of (benzylamine) : (m-phthalic acid) [(HL ) · (Hmpta )] (6)
Fig. 11 should be inserted here.
Fig. 12 should be inserted here.

ACCEPTED MANUSCRIPT
In the asymmetric unit of 6 there occupied one cation of benzylamine, and one
monoanion of m-phthalic acid, which is shown in Fig. 11. In the compound, there is a
pair of ion pair with no included solvent molecules accompanied, either. Different
from the published adduct [28], here only one COOH of the m-phthalic acid is
deprotonated to maintain the charge balance. The rms deviations of the rings with
C2-C7 and C10-C15 are 0.0061 Å, and 0.0099 Å, respectively, and both rings made
an angle of 122.2° with each other. The carboxylates twisted only by 4.4 (for
O(1)-C(8)-O(2)), and 12.8° (for O3-C9-O4) from the phenyl ring plane of the
m-phthalate, respectively, which is similar to the reported adduct from the phthalate in
which the carboxylates are almost coplanar with the phenyl ring also [29]. Both
carboxyl units intersected at an angle of 16.7° with each other. It is very clear that the
difference in bond lengths of the C-O within the C9-O3-O4 group (0.108 Å) is much
greater than the one found in the C8-O1-O2 anion (0.009 Å). Also the average bond
-
length for C-O (1.258 Å) in the COO (C8-O1-O2) is less than the C-O single bond
(C9-O3, 1.314(3) Å) and greater than the C=O double bond (C9-O4, 1.206(3) Å) in
the COOH group of the anion, this further supports our correct assignment of the
m-phthalate monoanion.
+
-
One anion and one cation form a bicomponent adduct [(HL ) · (Hmpta )] by the
+
bifurcated N-H···O hydrogen bond between the NH3 and both O atoms of the
carboxylate with N-O distances of 2.839(2)-3.197(2) Å. Two bicomponent adducts
+
-
[
(HL ) · (Hmpta )] were linked together by the N-H···O hydrogen bond between the
+
NH and the O atom of the carboxylate with N-O distance of 2.805(2) Å, and CH-O
3
association between the phenyl CH of the cation and the O of the carboxylate with
C-O distance of 3.552 Å to generate a tetramer having an inversion centre located at
the middle point of the two carboxylates.
Along a axis direction, the resulting tetramers were linked together by the
+
N-H···O hydrogen bond between the NH and the O atoms of the carboxylate with
3
N-O distance of 2.777(2) Å to produce a 1D chain running along the a axis direction.
Further connection through the interchain O-H···O hydrogen bond between the
-
COOH and the COO groups with O-O separation of 2.595(2) Å generates an overall

ACCEPTED MANUSCRIPT
2
D sheet extending parallel to the ac plane (Fig. 12). The 2D sheets displayed the
4
2
2
2
XXI R (12) (composed of the close joint R (4) and R (8) synthons), XX R (16)
4
1
4
2
2
2
2
(
composed of the close joint R (7), and R (10) synthons), and XXII R (9) ring
2 2 2
motifs. The interchain CH-O association between the p-CH of the anion and the OH
unit at the COOH with C-O distance of 3.245 Å, and CH -O association between the
2
CH spacer of the cation and the carbonyl unit of the COOH with C-O distance of
2
3
.476 Å were also found, which contribute also to the formation and stabilization of
the final 2D sheet structure.
+
2-
X-ray structure of (benzylamine) : (trimesic acid) [(HL ) · (Htma )] (7)
2
2
Fig. 13 should be inserted here.
Fig. 14 should be inserted here.
Compound 7 is a 1:2 salt composed of two cations of benzylaminium, and an
anion of hydrogen trimesate (Fig. 13), which crystallizes as triclinic block crystals in
the space group P-1. In the COOH (O(3)-C(16)-O(4)) group, two pairs of C-O bond
lengths (O(3)-C(16), 1.312(3) Å, and O(4)-C(16), 1.203(3) Å) are significantly
different with the large ꢀ value of 0.109 Å which is anticipated between the neutral
C-O and C=O bond distances [30]. The C-O bond lengths of the O2-C15-O1 group
are 1.242(3) Å, and 1.261(3) Å, respectively. The C-O bond lengths of the
O5-C17-O6 group are 1.264(3) Å, and 1.223(3) Å, respectively. The longer bond
O(2)-C(15) (1.261(3) Å) has almost the same length as that of the longer bond of
O5-C17 (1.264(3) Å). But there is relative significant difference between the shorter
bonds O(1)-C(15) (1.242(3) Å) and O(6)-C(17) (1.223(3) Å), the reason is that O(1)
takes part in more strong hydrogen bond than that of O(6) (Table 4). The rms
deviations of the rings C2-C7 and C9-C14 were 0.0017 Å and 0.0038 Å, respectively,
and both rings made a dihedral angle of 63.9° with each other. The rms deviation of
the ring with C18-C23 was 0.0098 Å. The phenyl ring C18-C23 of the anion
subtended the dihedral angles of 80°, and 24.4° with the above two rings, respectively.
The mean planes of the three carboxylate groups underwent slight twist from the
anion benzene ring with dihedral angles of 4.9(1)° for C15-O1-O2, 8.2(1)° for

ACCEPTED MANUSCRIPT
C16-O3-O4, and 20.2(1)° for C17-O5-O6, which are smaller than those
corresponding dihedral angles in the benzene-1,3,5-tricarboxylate trianion [31].
-
At every COO of the dianion there was bonded a cation by the N-H···O
+
hydrogen bonds from the NH with N-O distances of 2.704(3)-2.909(3) Å to form a
3
tricomponent adduct. Two tricomponent adducts were united into a six-component
+
-
aggregate through the N-H···O hydrogen bond from the NH , the COO and the
3
carbonyl unit of the COOH with N-O distances of 2.783(3) Å-2.953(3) Å, CH -O
2
association between the CH linker of the cation, the carbonyl and the OH units of the
2
COOH with C-O distances of 3.105 Å-3.477 Å, and O-C association between the
π
-
carbonyl unit of the COOH and the π-C of the COO with O-C distance of 3.196 Å, in
which the two tricomponent adducts at the six-component aggregate were antiparallel
to each other. It is worthy to point out that the O-C separation is slightly longer than
the archived value of 3.019(4) Å [32].
-
There were O-H···O hydrogen bonds between the COOH and the COO with
O-O separation of 2.565(3) Å which joined the six-component aggregates into 1D
chain running along the a axis direction, together with the N-H···O hydrogen bond
+
between the NH3 and the carboxylate with N-O distance of 2.709(3) Å. The 1D
chains were linked into 2D sheet extending parallel to the ab plane (Fig. 14) under the
assistance of the N-H···O hydrogen bonds, CH-π and CH -π associations. Herein the
2
+
N-H···O hydrogen bonds were from the NH and the carboxylate with N-O distances
3
of 2.713(3)-2.844(3) Å, CH-π associations existed between the phenyl CH of the
cation and the phenyl ring of the cation with C-Cg distances of 3.497-3.748 Å, and
CH -π association is established between the CH spacer of the cation and the phenyl
2
2
ring of the cation with C-Cg distance of 3.728 Å. The 2D sheets displayed XXIV
1
2
2
2
3
3
R (5), XXIII R (11), XXVII R (8), XXV R (10), and XXVI R (10) rings. The 2D
2
4
3
4
sheets were further expanded along the c axis direction to form 3D layer network
structure, where the neighboring sheet layers were slipped some distances from each
other along the a and b axis directions, respectively.
Conclusions

ACCEPTED MANUSCRIPT
Seven benzylaminium salts with different anions have been synthesized and
characterized by X-ray diffraction analysis. The structure analysis confirms that the N
atoms in the benzylamine are protonated in all the seven salts. Robust hydrogen bonds
in combination with other weak nonbonding associations led to the final generation of
distinct 2D-3D supramolecular networks. Although the organic acids utilized in this
work were different from each other, their structures display some certain common
structural features: in all of the crystal packing, the building blocks of 1-7 are
self-assembled via proton-transferred N-H···O hydrogen bonds, salts 4-7 possess the
additional O-H···O hydrogen bonds. The weak CH-O/CH -O, CH-π/CH -π, O-O, and
2
2
O-C associations also become prominent in the construction of the final
π
supramolecular networks. All structures have the 1D substructure (1D chain), from an
inspection of the function exhibited by each set of interactions, it seems that the intra-
and interchain noncovalent bonding interactions played equal importance in structure
propagation.
In this study, an intricate array of homosynthons and hetersynthons with small
2
1
2
1
2
1
and large sized ring motifs were observed including R (4), R (5), R (6), R (7),
1
2
2
2
2
2
2
2
2
2
2
2
2
2
2
3
3
3
2
R (6), R (7), R (8), R (9), R (10), R (11), R (16), R (6), R (9), R (10), R (8),
2
2
3
3
4
3
4
4
R (10), and R (12). But not all of them were observed repeatedly, as most of them
4
2
4
3
4
4
occurred only in some structures. Nevertheless R (8), R (10) and R (12) motifs
4
have been the most recurrently occurring ones in the present study and previous
reports. The seven structures discussed here further tell that the benzylaminium cation
is a good build block to be incorporated into organic salts so as to produce
diversiform and stable hydrogen-bonded structures.
Supporting Information Available: Crystallographic data for the structural analysis
have been deposited with the Cambridge Crystallographic data center, CCDC Nos.
1
029026 for 1, 1029027 for 2, 1029028 for 3, 1029029 for 4, 1029030 for 5, 1029031
for 6, and 1029032 for 7. Copies of this information may be obtained free of charge
from the +44(1223)336-033 or Email: deposit@ccdc.cam.ac.uk or www:
http://www.ccdc.cam.ac.uk.

ACCEPTED MANUSCRIPT
Acknowledgment
This research was supported by Zhejiang Provincial Natural Science Foundation
of China under Grant No. LY14B010006, the Shaoxing City Training Programs of
Innovation and Entrepreneurship of China for Undergraduates, the Open Foundation
of Key Laboratory of Chemical Utilization of Forestry Biomass of Zhejiang Province,
Zhejiang A & F University under Grant No. 2015CUFB02, Zhejiang Provincial
Natural Science Foundation of China under Grant No. LY14E030016; and the Open
Fund of Zhejiang Provincial Top Key Discipline of Forestry Engineering under Grant
No. 2014LYGCZ017.
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