Two seven-coordinate Mn(II) complexes derived from pentadentate ligands: Structural characterization and investigation of photophysical properties

Article abstract of DOI:10.1080/24701556.2017.1357620

Two mononuclear Mn(II) complexes derived from pentadentate ligands were prepared and characterized. Molecular structures of the complexes were determined by X-ray diffraction studies. Mn(II) ions in both structures are seven-coordinate with approximate pentagonal bipyramidal geometry where the pyridinediimine unit and phenolic or alcoholic oxygen atoms (N₃O₂) of the ligand are located at the pentagonal plane and two exogenous ligands at the axial positions. In the structure of [Mn(HL₂)Cl(CH₃OH)]·2(CH₃OH), methanol solvates link complex molecules into a 1D hydrogen-bonded chain. Emission spectra of the complexes show only one emission band in the 595–625?nm range upon excitation in the 585–615?nm range.

Full text of DOI:10.1080/24701556.2017.1357620

Inorganic and Nano-Metal Chemistry
ISSN: 2470-1556 (Print) 2470-1564 (Online) Journal homepage: http://www.tandfonline.com/loi/lsrt21
Two seven-coordinate Mn(II) complexes
derived from pentadentate ligands: Structural
characterization and investigation of
photophysical properties
Muhammet Kose
To cite this article: Muhammet Kose (2017): Two seven-coordinate Mn(II) complexes derived from
pentadentate ligands: Structural characterization and investigation of photophysical properties,
Inorganic and Nano-Metal Chemistry, DOI: 10.1080/24701556.2017.1357620
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Two seven-coordinate Mn(II) complexes derived from pentadentate ligands: Structural
characterization and investigation of photophysical properties
Muhammet Kose
Chemistry Department, Kahramanmaras Sutcu Imam University, Kahramanmaras, 46050,
Turkey.
Corresponding author Tel.: +90 344 280 1408; fax: +90 344 280 1352. E-mail address:
muhammetkose@ksu.edu.tr (Muhammet Kose)
Abstract
Two mononuclear Mn(II) complexes derived from pentadentate ligands were prepared and
characterized. Molecular structures of the complexes were determined by X-ray diffraction
studies. Mn(II) ions in both structures are seven-coordinate with approximate pentagonal
bipyramidal geometry where the pyridine-diimine unit and phenolic or alcoholic oxygen atoms
(N3O2) of the ligand are located at the pentagonal plane and two exogenous ligands at the axial
positions. In the structure of [Mn(HL2)Cl(CH3OH)]·2(CH3OH), methanol solvates link complex
molecules into a 1D hydrogen bonded chain. Emission spectra of the complexes shows only one
emission band in the 595-625 nm range upon excitation in 585-615 nm range.
Keywords
Seven-Coordinate Mn(II); Pentadentate ligand; Molecular structure; Emission spectra
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1.
Introduction
Nitrogen–oxygen donor pentadentate ligands and their metal complexes have received
considerable attention owing to their applications in several areas including catalysis, transport
processes and mimicking of several biological compounds [1–5]. Many ligand nitrogen– oxygen
donor systems have been studied to mimic the function of natural carriers in recognizing and
transporting specific molecules or ions and for understanding and reproducing the catalytic
activity of metallo-enzymes [6]. Pentadentate (N3O2 or N5 type) Schiff base ligands derived from
2,6-diacetylpyridine and 2,6-diformylpyridine are of interest to prepare macrocyclic and acyclic
Schiff base metal complexes [7–11]. These ligands often bind to the metal ions with all five
donor atoms resulting in six or seven-coordinate complexes (with one or two auxiliary ligands)
depending on the metal ions. The Mn(II) ion, for example, generally forms seven-coordinate
complexes with these pentadentate Schiff base ligands [12–16]. Pentadentate Schiff base ligands
derived from 2,6-diacetylpyridine and 2,6-diformylpyridine provide pentagonal coordination site
to obtain seven-coordinate Mn(II) complexes with two auxiliary anions [16]. The factor leading
to seven-coordinate structure is that the rigid pyridine-diimine section in these ligands constrains
three nitrogen donors to be planar and to occupy two bite angles of 136.41(15)°, leaving enough
space for two further donors in the same plane resulting in a pentagonal plane [16].
Recently, we reported mono-, di- and tri-nuclear seven-coordinate Mn(II) complexes
derived from 2,6-diformylpyridine and 2-aminophenol [17]. In continuation of our interest in
seven-coordinate Mn(II), here we report the synthesis, structural characterization, thermal and
photophysical properties of two Mn(II) complexes.
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2. Experimental
2.1 General methods
All starting materials and organic solvents were purchased from Sigma-Aldrich and used
as received, unless noted otherwise. 2,6-Diformylpyridine was prepared by oxidation of 2,6-
pyridinedimethanol using manganese dioxide according to the literature method [18] and used
without further purification. IR spectra were performed on a Perkin Elmer Paragon 1000 PC.
1
CHN analyses were performed using a CE-440 Elemental analyser. The H NMR spectra were
performed on a Bruker Avance 500. The electronic spectra in the 200–900 nm range were
obtained on a Shimadzu UV-1800 UV-Vis spectrophotometer. The single-photon fluorescence
spectra were collected on a Perkin Elmer LS55 luminescence spectrometer. The thermal analyses
of the complexes were performed on a Perkin Elmer Pyris Diamond.
2.2 X-ray structures solution and refinement for the complexes
Data collection and cell refinement for X-ray crystallography were completed using a
Bruker APEX2 CCD diffractometer and data reduction was performed using Bruker SAINT.
Diffraction data were measured at 150(2) K using Mo-
radiation with a Bruker ApexII
diffractometer [19]. SHELX-2014 was used to solve and refine the structures [19]. SADABS-
2009/1 was used for absorption correction [20]. The structure was solved by direct methods and
refined on F2 using all reflections using the SHELXTL software [21]. All the non-hydrogen
atoms were refined using anisotropic atomic displacement parameters. Hydrogen atoms bonded
to carbon atoms and hydrogen atoms bonded to O4 and O5 atoms in
[Mn(HL1)(Cl)(CH3OH)]∙2(CH3OH) were inserted at calculated positions using a riding model.
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Rest of the H atoms bonded to oxygen atoms in both complexes were located from difference
maps and refined freely. In [Mn(HL1)(Cl)(CH3OH)]∙2(CH3OH), in each complex molecule, one
of the phenolic OH groups is deprotonated and the hydrogen atom bonded to the phenolic
oxygen atom is disordered over two phenolic oxygen atoms (O1 and O2) and their occupancies
were fixed with 0.5-0.5. Details of the crystal data and refinement are given in Table 1.
2.3 Synthesis of the Schiff base ligands (H2L1 and H2L2)
The ligands were synthesised by the reaction of 2,6-diformylpyridine (0.135 g, 1 mmol)
and 2-amino-p-cresol (0.246 g, 2 mmol) or 2-aminobenzylalcohol (0.246 g, 2 mmol) in refluxing
methanol. After four hours reflux, the solvent was removed on a rotary evaporator. The ligand
H2L1 was obtained as yellow powder while H2L2 as yellowish oil. The ligands were
characterized by 1H NMR, IR spectra and micro (CHN) analysis.
H2L1∙1/2H2O: Yellow powder, yield: 0.301
g
(85%). Elemental analyses for
C21H19N3O2∙1/2H2O (354.4 g/mol): Calcld.: C, 71.17; H, 5.69; N, 11.86. Found: C,70.85;
H,5.45; N,11.60%. IR (KBr, cm-1): 3405, 2945, 1620, 1572, 1492, 1351, 1245, 1182, 1087, 1032,
1
984, 960 cm-1. NMR: H (CDCl3 as solvent, δ ppm) 10.15 (br, PhOH), 8.72 (s, 2H, -N=CH),
8.18 (d, 2H pyridine), 7.83 (t, 1H pyridine), 7.11(s, 2H, aromatic), 6.95 (d, 2H, aromatic), 6.89
(d, 2H, aromatic), 2.21 (s, 6H, C-CH3), 1.62 (br, H2O).
H2L2: Yellowish oil, yield: 0.322 g (93%). Elemental analyses for C21H19N3O2 (345.4 g/mol):
Calcld.: C, 73.03; H, 5.54; N, 12.17. Found: C,72.86; H,5.39; N,11.83%. IR (ATR, cm-1): 3415,
1
2945, 2920, 1624, 1577, 1495, 1353, 1175, 1081, 1035, 974, 955 cm-1. NMR: H (CDCl3 as
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solvent, δ ppm) 8.75 (s, 2H, -N=CH), 8.17(d, 2H pyridine), 7.88 (t, 1H pyridine), 7.09-7.28 (m,
8H aromatic), 4.61 (s, 4H, C-CH2-OH).
2.4 Synthesis of [Mn(HL1)(Cl)(CH3OH)]∙2(CH3OH)
To a refluxing solution of the ligand H2L1∙1/2H2O (0.354 g, 1 mmol) in methanol (30 mL),
MnCl2.4H2O (0.197 g, 1 mmol) was added resulting in a red clear solution. The reaction solution
was further refluxed for 4 hours. Upon cooling to the room temperature, a red precipitate formed
was filtered and washed with cold MeOH (5 mL) and diethyl ether (10 mL). Single crystals for
X-ray diffraction study were obtained by slow diffusion of diethylether into a methanol solution
of the complex.
Yield: 0.352 g, 66% (based on Mn(II)). Colour: Red. Elemental analysis data: Anal. (%)
Calculated for [Mn(HL1)(Cl)(CH3OH)]∙2(CH3OH) C24H30N3O5ClMn (530.90 g/mol): C, 54.30;
H, 5.70; N, 7.91. Found (%): C, 54.14; H, 5.35; N, 7.63. IR (KBr, ν, cm−1): 3405, 2952, 1610,
1571, 1485, 1353, 1260, 1170, 1080, 984, 960, 560, 450 cm-1. eff (B.M)/Mn= 5.42.
2.5 Synthesis of [Mn(H2L2)(NCS)2]
The ligand H2L2 (0.354 g, 1 mmol) was dissolved in MeOH (30 mL), Mn(OAc)2.4H2O
(0.245 g, 1 mmol) was added and followed by addition of NaNCS (0.162 g, 2 mmol). Upon
addition of NaNCS, a yellow precipitate formed and the product was collected and washed with
diethyl ether (10 mL). Single crystals suitable for X-ray diffraction study were obtained from a
slow evaporation of the complex in acetonitrile.
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Yield: 0.381 g, 73% (based on Mn(II)). Colour: Yellow. Elemental analysis data: Anal. (%)
Calculated for [Mn(H2L2)(NCS)2] C23H19N5O2S2Mn (516.49 g/mol): C, 53.48; H, 3.71; N,
13.56. Found (%): C, 53.14; H, 3.35; N, 13.10. IR (KBr, ν, cm−1): 3380, 2955, 2072, 1603,
1575, 1470, 1350, 1255, 1165, 1073, 985, 968, 548, 462 cm-1. eff (B.M)/Mn= 5.51.
3.
Results and Discussion
The ligands H2L1 and H2L2 were prepared according to reported methods [22, 23] by
reacting one equivalent of 2,6-diformylpyridine with two equivalents of 2-amino-4-methylphenol
or 2-aminophenol in methanol (Fig. 1), the yellow products were obtained after stirring for 30
min at room temperature. The ligands are soluble in most organic solvents such as methanol,
ethanol, chloroform, dimetylformamide and not soluble in water. Each molecule has two imine
groups (C=N) and two 4-methylphenol or benzylalcohol units, one each side of the pyridine.
Micro analysis results are given in the experimental section and are in well agreement with the
1
theoretical values. The H spectra of the ligands were also recorded in CDCl3 and both ligands
show mirror symmetry in the CDCl3 solution. The ligand H2L1 was previously synthesised by
our group and 1H NMR data are well agreed with the literature data [24]. The 1H-NMR spectrum
of the H2L2
4.61 ppm corresponding to the protons of the alcohol group
5 ppm was assigned to azomethine protons (–N=CH–).
7.28-8.17.
protons (Ph-CH2-O
The aromatic protons were seen
The infrared spectra of the free ligands and their Mn(II) complexes were obtained. The
infrared spectra of the free ligands were compared with those of the Mn(II) complexes to access
the coordination of the ligands to Mn(II) ion. The FT-IR spectra of the Schiff base ligands H2L1
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and H2L2, the absence of bands due to the aldehyde group ν(C=O) and appearance of a new band
at 1620 and 1624 cm-1, respectively, confirming the formation of Schiff base ligands. The
azomethine group –CH=N stretching frequencies shifted to lower values in the spectra of the
complexes indicating the coordination of azomethine nitrogen to the Mn(II) ion. In the spectra of
complex [Mn(H2L2)(NCS)2]∙2(CH3CN), a sharp peak due to thiocyanate stretch was observed at
2072 cm-1.
Thermal studies of the complexes were performed under nitrogen atmosphere in the
temperature range of 20–1000 C. The thermal curves for the complexes are given in the
supplementary
file
(Figs.
S1&S2)
Thermal
decomposition
of
the
[Mn(HL1)(Cl)(CH3OH)]∙2CH3OH has four decomposition steps all of which are endothermic
processes, in the first two steps, about 5% of the mass was lost in the temperature range of 100-
300 C. This loss may be attributed to gradual loss of methanol solvates in the complex. In the
third step, approximately 17% of the sample was removed from the structure in the range of 300-
500 C; this was attributed to loss of coordinated chloride ion and methanol molecule. The rest
of the organic moiety decomposes gradually up to high temperature leaving metal oxides as a
final residue. Chemical structure of complex [Mn(H2L2)(NCS)2] was thermally stable up to 270
C. The complex shows three thermal decomposition steps accompanied with endothermic
peaks. In the first two steps, approximately 16.83% and 18.23% of total mass were lost in the
temperature range of 270-500 C. Gradual decomposition of the complex continued up to high
temperatures leaving metal oxide as final products.
The magnetic susceptibilities of the complexes were determined using the Evans balance at room
temperature
[25]
values
for
the
complexes
eff
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[Mn(HL1)(Cl)(CH3OH)]∙2(CH3OH) and [Mn(H2L2)(NCS)2] are 5.42 and 5.51 B.M.,
respectively, within the range of typical high spin d5 manganese(II) complexes [26, 16].
3.1 Molecular structure of [Mn(HL1)(Cl)(CH3OH)]∙2(CH3OH)
Red crystals of complex suitable for X-ray diffraction studies were grown from slow
diffusion of diethyether into methanol solution of the complex. The complex crystallises as
[Mn(HL1)(Cl)(CH3OH)]∙2(CH3OH). The structure of the complex was solved in the
orthorhombic space group Pbcn. Molecular structure of the complex with atom numbering is
shown in Fig. 2. Asymmetric unit of the complex contains mononuclear complex molecule and
two methanol solvates. The Mn(II) ion is seven-coordinate with approximate pentagonal
bipyramidal geometry, bonded to the pyridinediimine unit and phenolic oxygen atoms (N3O2) of
the ligand in the pentagonal plane, and to an chloride ion and an oxygen atom of a methanol
molecule at the axial positions. Pyridinediimine donors provide angles of 67.96(15)° (N1-Mn1-
N2) and 68.75(14)° (N2-Mn1-N3) which are slightly distorted from an ideal value of 72° for a
pentagonal plane (Table 2).
The manganese(II) complexes reported here structural resemble to the manganese
complexes reported in literature [13-16]. Seven-coordination in those reported complexes has
been ascribed to the macrocyclic nature of the ligand and the stable planarity of the ligand
system. Another important factor is that a high spin d5 ion has no stereochemical preferences.
It is informative to compare the crystal structure of [Mn(HL1)(Cl)(CH3OH)]∙2(CH3OH) with the
Mn(II) complex of the ligand prepared from 2,6-diformylpyridine and 2-aminophenol. The
related Mn(II) complex in the literature was synthesised and structurally characterized by our
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group [17]. In both the complex [Mn(HL1)(Cl)(CH3OH)]∙2(CH3OH) and the published complex,
the Mn(II) ions are seven-coordinate and they both have similar Mn-N(or O) distances.
However, the charge of Mn(II) in the complex reported in the literature was balanced by two
chloride ions and phenolic oxygen atoms remained protonated. Thus, the complex molecules are
not dimerised by Ph-O∙∙∙H-O-Ph hydrogen bonds as seen in the complex reported here.
In the complex reported in this paper, one of the phenolic OH groups is deprotonated and
the other remains protonated. The charge of the complex is then balanced by a chloride anion
and one of phenolate groups of the ligand. The proton of phenolic group in the ligand is
disordered over two phenolic oxygen atoms. Two complex molecules are dimerized by two
component (O-H∙∙∙∙O) hydrogen bonds (Table 3). Coordinated and non-coordinated methanol
molecules are involved in hydrogen bonding with each other linking complex molecules into 1D
hydrogen bond chain shown in Fig. 3.
In the structure, the two outer rings twisted with respect to the central pyridine ring. The
mean planes of C1-C6 and C15/C21 are at 1.619(27) and 12.994(24) to the central (C9-C14)
ring, respectively. There are π-π interactions in the structure stabilising the structure in the solid
state. The C12-C15 section of one of the complex molecule is stacked with the C7-C10 section
of an adjacent molecule under symmetry operation of 1/2-x, -1/2+y, z. The C14 and C8* atoms
are separated by 3.300 Å. The π-π interactions in the structure is shown in Fig. 4.
3.2 Molecular structure of [Mn(H2L2)(NCS)2]∙2(CH3CN)
Yellow crystals of complex suitable for X-ray diffraction studies were grown from slow
evaporation of the complex in acetonitrile. The complex was found to crystallise as two
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acetonitrile solvates per complex molecule. The complex was found to crystallise in the triclinic
space group P-1. The complex molecule shows no crystallography imposed symmetry and
molecular structure of the complex with atom numbering is shown in Fig. 5. From the X-ray data
the imine bond distances (N1-C8 and N3-C14) were found to be 1.2796(16) and 1.2766(16) Å
which confirm the double bond character of these bonds (Table 2). The structure contains a
single seven-coordinate manganese(II) ion that is bound to the N3O2 donor set of the
pentadentate ligand which forms a pentagonal plane, two thiocyanate ions are bound via the
nitrogen donor in the axial positions. The angle N4-Mn-N5 is 174.42(4)° and slightly deviated
from an ideal value of 180°. This may be due to hydrogen bond interactions of the thiocyanate
ions.
The Mn(II) ion has an expected approximate pentagonal bipyramidal geometry where the
donors of the pentagonal plane are three pyridine diimine nitrogens and two oxygen atoms. One
of the axial thiocyanate ions is hydrogen bonded to one of the OH groups of the ligand
(O2-H2···S1) of an adjacent complex molecule and these two concordant hydrogen bonds result
in a hydrogen bonded dimer with a R2 (12) motif (Fig. 6). One of the acetonitrile solvate
2
involves in hydrogen bonding with OH group of the ligand (Table 3).
In the structure, the two outer rings considerably twisted with respect to the pyridine ring.
The mean planes of C1-C6 and C15/C21 are at 1.619(27) and 12.994(24) to the central (C9-
C14) ring, respectively. There are π-π interactions in the structure stabilizing the structure in the
solid state. The C12-C15 section of one of the complex molecule is stacked with the C7-C10
section of an adjacent molecule under symmetry operation of 1/2-x, -1/2+y, z. The C14 and C8*
atoms are separated by 3.300 Å.
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3.3 UV-Vis. and photoluminescence spectra of the complexes
The UV-Vis absorption spectra of the complexes (10-5 M) were investigated in the 250-
800 nm range in methanol. The UV–vis spectrum of [Mn(HL1)(Cl)(CH3OH)]∙2(CH3OH) shows
two absorption maximas at 285 and 520 nm (Fig. 7). The band at 285 nm with three consequent
shoulders at 315, 350, 390 nm in the spectra may due to π-π* transitions of aromatic groups and
azomethine linkage (-C=N-). The absorption at 520 nm with lower intensity can be assigned
charge transfer band (M→L). Complex [Mn(H2L2)(NCS)2] exhibits absorption bands at 285 and
420 nm in methanol solution (Fig. S3). The bands at 285 with a shoulder at 345 nm can be
attributed to the -
-420 nm range was assigned
to charge transfer transition. No d-d transitions were observed for both complexes at the
concentration studied. The single-photon fluorescence spectra of the complexes were collected
on a Perkin Elmer LS55 luminescence spectrometer in the solid state. The emission and
excitation spectra of [Mn(H2L2)(NCS)2] and [Mn(HL1)(Cl)(CH3OH)]∙2(CH3OH) are shown in
Figs. 8&S4. In the excitation spectra of the complexes, one excitation band was observed in the
585-615 nm range. Upon excitation in the 585-615 nm range, both complexes exhibit only one
emission band in the 595-625 nm range in the solid state.
4. Conclusions
In this study, two Mn(II) complexes of pentadentate ligands were successfully prepared
and characterized by the spectroscopic and analytic methods. Molecular structure of the
complexes was determined by single crystal X-ray diffraction study. The Mn(II) ions in both
complexes [Mn(HL1)(Cl)(CH3OH)]∙2(CH3OH) and [Mn(H2L2)(NCS)2]∙2(CH3CN) are seven-
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coordinate with approximate pentagonal bipyramidal geometry. Solid state emission spectra of
the complexes shows only one emission band in the 595-625 nm range in the solid state upon
excitation in the 585-615 nm range.
Supplementary Information
Crystallographic data have been deposited with the Cambridge Crystallographic Data Centre,
CCDC
numbers
for
the
complexes
[Mn(HL1)(Cl)(CH3OH)].2(CH3OH)
and
[Mn(H2L2)(NCS)2].2(CH3CN) are 1452104 and 1452105, respectively. Copies of this
information can be obtained from The Director, CCDC, 12 Union Road, Cambridge, CB2 1EZ,
UK (fax: +44 1223 335033; email deposit@ccdc.cam.ac.uk or http://www.ccdc.cam.ac.uk).
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Table 1 Crystallographic data for the complexes.
Identification code
Empirical formula
Formula weight
Crystal size (mm3)
Crystal color
Crystal system
Space group
Unit cell a (Å)
b (Å)
[Mn(HL1)(Cl)(CH3OH)].2(CH3OH [Mn(H2L2)(NCS)2].2(CH3CN
C24H30Cl MnN3O5
530.90
C27H25MnN7O2S2
598.60
0.37 x 0.24 x 0.21
Red
0.50 x 0.37 x 0.17
Yellow
Orthorhombic
Pbcn
Triclinic
P-1
20.290(3)
12.1646(17)
20.038(3)
90
9.174(3)
10.118(3)
16.052(5)
78.691(4)
87.111(4)
81.554(4)
1444.8(8)
2
c (Å)
 (°)
90
 (°)
90
 (°)
Volume (Å3)
4945.9(12)
8
Z
Abs. coeff. (mm-1)
Refl. collected
0.682
0.638
40968
16907
99.8 %
89.4 %
Ind. Refl. [Rint]
5079 [0.0737]
0.0737, 0.1941
0.0910, 0.2036
1452104
8666 [0.0181]
0.0318, 0.0868
0.0385, 0.0933
1452105
R1, wR2 [I>2 (I)]
R1, wR2 (all data)
CCDC number
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Table 2 Selected bond lengths [Å] and angles [°] for the complexes.
[Mn(HL1)(Cl)(CH3OH)].2(CH3OH) [Mn(H2L2)(NCS)2].2(CH3CN
)
Mn(1)-N(1)
2.348(4)
2.311(4)
2.308(4)
2.211(4)
2.263(3)
2.285(4)
2.5252(16)
-
2.4577(12)
2.2839(12)
2.5299(11)
2.3404(11)
2.2529(10)
-
Mn(1)-N(2)
Mn(1)-N(3)
Mn(1)-O(1)
Mn(1)-O(2)
Mn(1)-O(3)
Mn(1)-Cl(1)
-
Mn(1)-N(4)
2.1495(13)
2.1693(12)
69.34(4)
137.48(4)
68.41(4)
73.23(4)
-
Mn(1)-N(5)
-
N(1)-Mn(1)-N(2)
N(1)-Mn(1)-N(3)
N(2)-Mn(1)-N(3)
O(1)-Mn(1)-O(2)
O(3)-Mn(1)-Cl(1)
67.96(15)
136.41(15)
68.75(14)
81.38(13)
177.60(12)
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N(4)-Mn(1)-N(5)
-
174.42(4)
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Table 3 Hydrogen bond parameters [Å and °].
[Mn(HL1)(Cl)(CH3OH)].2(CH3OH)
D-H∙∙∙∙A
d(D-H)
d(H∙∙∙∙A)
d(D∙∙∙∙A)
<(DHA)
169 (17)
O1-H1∙∙∙∙O1i
0.78 (12)
1.67 (11)
2.448 (7)
O(2)-H(2)∙∙∙∙O(2)i
O(3)-H(3)∙∙∙∙O(5)
0.82 (12)
0.79 (7)
1.67 (11)
1.94 (8)
2.461 (7)
2.705 (6)
162 (15)
162 (8)
Symmetry transformations used to generate equivalent atoms: i: -x+1, y, -z+1/2 ii: x, -y, z-1/2.
[Mn(H2L2)(NCS)2].2(CH3CN)
O(1)-H(1C)∙∙∙∙N(7)
O(2)-H(2)∙∙∙∙S(1)i
0.73(2)
2.20(2)
2.922(2)
166(2)
0.821(19)
2.500(19)
3.2127(12)
145.9(16)
Symmetry transformations used to generate equivalent atoms: i: -x+1,-y+2,-z+1
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N
N
N
N
N
N
O H
H O
O H
H O
H 2 L 2
H 2 L 1
Fig. 1 Pentadentate ligands used in this study.
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Fig. 2 Molecular structure of complex molecule in [Mn(HL1)(Cl)(CH3OH)]∙2(CH3OH),
hydrogen atoms and two methanol solvates are omitted for clarity.
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Fig. 3 Packing diagram of [Mn(HL1)(Cl)(CH3OH)]∙2(CH3OH) showing hydrogen bonding
interactions, hydrogen atoms are omitted for clarity.
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Fig. 4 π-π interactions in [Mn(HL1)(Cl)(CH3OH)]∙2(CH3OH), hydrogen atoms are omitted for
clarity (symmetry operation* 1/2-x, -1/2+y, z).
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Fig. 5 Molecular structures of complex [Mn(H2L2)(NCS)2]∙2(CH3CN), two acetonitrile solvates
are not shown for clarity.
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Fig. 6 Hydrogen bonded dimers in [Mn(H2L2)(NCS)2]∙2(CH3CN), hydrogen bonds are shown as
dashed lines.
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2
1
0
250
300
350
400
450
500
550
600
Wavelength (nm)
Fig. 7 UV-vis spectrum of [Mn(HL1)(Cl)(CH3OH)]∙2(CH3OH) in methanol (10-5 M).
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1000
900
800
700
600
500
400
300
200
100
0
Excitation
Emission
570
580
590
600
610
620
630
640
Wavelength (nm)
Fig. 8 Excitation and emission spectra of [Mn(H2L2)(NCS)2] in the solid state.
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