Syntheses, Crystal Structures, and Properties of Three Novel Silver

Subscriber access provided by MT ROYAL COLLEGE

Article

Syntheses, Crystal Structures and Properties of Three Novel Silver-Organic Frameworks Assembled from 1,2,3,5Benzenetetracarboxylic Acid Based on Argentophilic Interactions Changkun Xia, Yuanyuan Min, Kai Yang, Wen Sun, Deli Jiang, and Min Chen Cryst. Growth Des., Just Accepted Manuscript • DOI: 10.1021/acs.cgd.7b01319 • Publication Date (Web): 26 Feb 2018 Downloaded from http://pubs.acs.org on February 27, 2018

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 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 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 21 1 2 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

Crystal Growth & Design

Syntheses, Crystal Structures and Properties of Three Novel Silver-Organic Frameworks Assembled from 1,2,3,5-Benzenetetracarboxylic Acid Based on Argentophilic Interactions Chang-Kun Xia,* Yuan-Yuan Min, Kai Yang, Wen Sun, De-Li Jiang, Min Chen School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, China

ABSTRACT: Three novel silver(I) metal-organic coordination polymers constructed from 1,2,3,5-benzenetetracarboxylic acid with different deprotonation degree, namely, [Ag2(H2btec)(H2O)]

(1),

[Ag3(Hbtec)]

(2),

and

[Ag4(btec)]

(3)

(H4btec

=1,2,3,5-benzenetetracarboxylic acid) have been synthesized with hydrothermal methods and characterized by elemental analysis, IR, TGA, and single crystal X-ray diffraction. The Ag(I) atoms show versatile coordination sphere in the three different complexes, great supramolecular structure difference demonstrated due to the coordination modes change of the H4btec ligands. Ag(I) dimers bridged by H2btec2ligands into a three-dimensional framework was observed in complex 1. An unprecedented talon-like Ag(I) hexamer unit was obtained in complex 2, which acts as building unit connects with Hbtec3- into (5,10)-connected MoGe2 type framework. A one-dimensional Ag(I) chain built with Ag(I) tetramer units demonstrated in complex 3, each btec4- ligand bridges six such chains into a three-dimensional framework. On the other hand, the weaker argentophilic interactions bridge the talon-like hexamers into a bead-like Ag(I) chain in complex 2, while such weak interactions bridge the zigzag Ag(I) chains into a two-dimensional Ag(I) sheet in complex 3. Thermal stabilities, photoluminescence, and antibacterial activities of complexes 1–3 were also examined.

INTRODUCTION Metal-organic coordination polymers have attracted considerable attention because of their potential applications as functional materials as well as their structural diversity 1

ACS Paragon Plus Environment

Crystal Growth & Design 1 2 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

Page 2 of 21

and intriguing topologies.1-4 However, the synthesis of complexes with predictable assembly is still a great challenge due to the limited understanding of the weak interactions in the metal complexes. The formation of coordination complexes is influenced by many factors such as solvent, pH value of the reaction mixture, molar ratio of the components, reaction temperature, as well as the coordination nature of the metal ion and organic ligands, the influencing information on the final supramolecular structure is far from well understood.5-10 Therefore, careful selection of suitable organic ligands and metal centers for construction of supramolecular architecture with weak interactions is an important strategy in crystal engineering.11, 12 Ag(I) is among the most labile metal ion due to its d10 electronic configuration with versatile coordination number varying from 2 to 9. As documented, silver(I) ion demonstrates linear, trigonal, squareplanar, square-pyramidal, trigonal-bipyramidal, tetrahedral, and octahedral coordination geometries with high affinity to both nitrogen and oxygen atoms.13-15On the other hand, despite the repulsion expected between two closed-shell metal cations, the silver(I) ion is apt to form short Ag-Ag contacts that have been structurally characterized, range from dimer, trimer, tetramer, hexamer16-19 to intricate high-nuclearity.20-24 The Ag-Ag contacts play important contribution to the formation of such complexes and thus lead special properties. In the past years, a series of silver(I) complexes based on adjacent dense polycarboxylate ligands such as 1,2,3- benzenetricarboxylic acid,25 1,2,3,4benzenetetracarboxylic

acid,

1,2,3,4,5-benzenepentacarboxylic

acid,20,22

and

1,1’-biphenyl-2,2’,6,6’-tetracarboxylic acid23 have been prepared and structurally characterized. Compared with the other aromatic polycarboxylic acids, such as benzenedicarboxylic

acid,26-28

1,2,4-benzenetricarboxylic

acid,29,30

1,3,5-benzenetricarboxylic acid,31,32 and 1,2,4,5-benzenetetracarboxylic acid,33,34 the argentophilicity plays more obvious role in constructing new fascinating structures in those Ag(I) complexes constructed with adjacent dense polycarboxylate ligands. As a coinage d10 metal, Ag(I) coordination complexes are widely studies for photoluminescent properties, and the Ag–Ag interactions have an important influence on the energy gap between the ground and excited states and could contribute to the 2


Page 3 of 21 1 2 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


photoluminescent

properties,

which

may

lead

interesting

photoluminescent

material.19,35 Through single point energy calculation based on the experimental geometry, Alisir et al found out the direct Ag-Ag interactions as well as larger HOMO-LUMO gap could enhance the luminescent emission.36 On the other hand, silver-based coordination polymers as well as silver nanoparticles show interesting antibacterial properties, and it has been reported that the bacterial action of silver-based material arises from the release of Ag+ ions, which diffused into the bacterial membrane and disrupt cell membrane proteins.37-41 However, it is still a great challenge to design and prepare new silver-based materials with high activity and durability for bactericidal applications. Moreover, despite considerable antibacterial silver(I) complexes have been documented, the effects of Ag-Ag interactions on antibacterial activity and mechanism in framework structure is far from clear. Jones et al found the weaker Ag-O coordination bonding, together with weaker Ag-Ag interactions, facilitate ligand loss, thus increase silver(I) ion release.42 Razali et al reported the carbene dinuclear complexes showed low antibacterial activity compare with corresponding mononuclear complexes for the formation of Ag-Ag bonding, which makes the silver atoms bond so firmly and difficult to release.43 While in other case, the formation of Ag-Ag bonding changed the coordination modes of the sulfonamides to the silver ions, and enhanced the antibacterial activity compare with no Ag-Ag interaction one. Therefore the study of Ag-Ag interactions on antibacterial activity and mechanism is a long term challenge, and great deal of work is required to extend the knowledge.44 In order to enrich this interesting field, in this work, we used 1,2,3,5benzenetetracarboxylic acid, a derivative of the well explored adjacent dense polycarboxylate ligand, 1,2,3-benzenetricarboxylic acid as ligand, obtained three novel silver(I) complexes with Ag-Ag contacts. 1,2,3,5-benzenetetracarboxylic acid (H4btec) has been proved to be an ideal ligand to form coordination compounds with unique structures and interesting properties.45-47 Different from well reported 1,2,3-benzenetricarboxylic acid, the H4btec has a 5-carboxyl group, which could not only acts hydrogen bonding donor and acceptor, but also form covalent bonding with 3



the Ag(I) metal ion. Herein, three different Ag(I) coordination polymers, namely, [Ag2(H2btec)(H2O)] (1), [Ag3(Hbtec)] (2), and [Ag4(btec)] (3), will be presented. All the complexes are obtained with hydrothermal reaction at 100 °C, the Ag(I) atoms are four and five coordinated in both complexes 1 and 2, but involving Ag-C bonding in 2, while three, four, and five coordinated in complex 3. Through the self-assembly reaction of AgNO3 and H4btec, we have successfully isolated three different silver(I) coordination complexes based on the different degree of deprotonation of the H4btec ligands by changing the pH value of the reaction mixture. Interestingly, Ag(I) dimer displayed in complex 1, while talon-like Ag(I) hexamer and one-dimensional Ag(I) chain demonstrated in complexes 2 and 3, respectively. The thermal stabilities, luminescent properties, and antibacterial properties of complexes 1-3 are also being discussed.

EXPERIMENTAL SECTION Materials and physical measurements All the solvents and reagents were purchased commercially available and used without further purification. Elemental analyses of C and H were measured with an Elementar Vario EL III analyzer and the IR spectra (KBr pellets) were recorded in the range of 400–4000 cm–1 with a Nicolet Magna 750 FT-IR spectrometer. The fluorescence measurements were performed on ground powder samples at room temperature using an Edinburgh Analytical Instrument FLS920. The studies of thermal gravity analysis (TGA) were carried out on a NETSCHZ STA-499C thermoanalyzer at a heating rate of 10 °C·min–1 in a nitrogen atmosphere (30–800 °C range). X-ray powder diffractions (XRPD) were collected at room temperature with a Bruker D8 Advanced diffractometer with Cu-Kα radiation (λ =1.5418Å). The release ratio of Ag+ ions was performed on an Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES) (Optima 200 DV, made by Perkin Elmer Company). Preparation of Complexes 1-3 Synthesis of [Ag2(H2btec)(H2O)] (1). A mixture of 15 mL H2O, 0.127 g (0.5 mmol) H4btec, 0.04 g (1.0 mmol) NaOH were dissolved in a 20 mL vial to form a clear 4


Page 4 of 21

Page 5 of 21 1 2 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


solution. Then AgNO3 (0.170 g, 1.0 mmol) was added with the final reaction mixture pH at 2.4, The vial was sealed in Teflon-lined stainless steel vessel, heated at 100 °C for 3 days, and cooled to room temperature. Colorless stick-like crystals of complex 1 were obtained and dried in air (65% yield, based on H4btec). Elemental Anal. Calc. for C10H6Ag2O9: C, 24.72; H, 1.24. Found: C, 24.85; H, 1.36. IR (KBr pellet): 3518(s), 3422(s), 2362(m), 1704(s), 1660(w), 1579(m), 1529(m), 1365(m), 1262(s), 1149(w), 1077(w), 907(w), 775(m), 715(w), 675(w), 597(m), 435(w). Synthesis of [Ag3(Hbtec)] (2).The preparation of [Ag3(Hbtec)] was similar to that of complex 1, except that more NaOH (0.06 g, 1.5 mmol) and AgNO3 (0.255 g, 1.5 mmol) were used with the final reaction mixture pH at 4.0. Colorless block-like crystals of complex 2 were obtained and dried in air (66% yield based on H4btec). Elemental Anal. Calc. for C10H3Ag3O8: C, 20.90; H, 0.53. Found: C, 20.83; H, 0.51. IR (KBr pellet): 3436(s), 2922(vw), 2360(s), 1684(m), 1610(w), 1560(s), 1450(w), 1406(w), 1355(s), 1256(m), 1178(w), 1081(w), 817(w), 769(vw), 707(w), 584(w), 404(w). Synthesis of [Ag4(btec)] (3). The preparation of [Ag4(btec)] was similar to that for complex 1, except double NaOH (0.08 g, 2.0 mmol) and AgNO3 (0.34 g, 2.0 mmol) with the final reaction mixture pH at 6.2. Colorless prism crystals of 3 were obtained and dried in air (72% yield based on H4btec). Elemental Anal. Calc. for C10H2Ag4O8: C, 17.62; H, 0.30. Found: C, 17.76; H, 0.42. IR (KBr pellet): 3305(m), 2359(s), 1566(s), 1444(m), 1357(s), 1069(w), 928(w), 838(w), 759(w), 713(m), 590(w), 525(w), 403(w).

Crystal Structure Determination. Suitable single crystals of complexes 1-3 were carefully selected under an optical microscope and glued to thin glass fibers. The diffraction data were collected on a siemens SMART CCD diffractometer with graphite-monochromated Mo-Ka radiation (λ=0.71073Å) at 298 K. An empirical absorption correction was applied using the SADABS program.48 The structures were solved by direct methods and refined by full-matrix least-squares methods on F2 by using the SHELX-2014 program package.49 All non-hydrogen atoms were refined 5



Page 6 of 21

anisotropically. Hydrogen atoms of btec phenyl ring were generated geometrically. The crystallography details for the structures determination of complexes 1-3 are presented in Table 1. Selected bond distances and angles are listed in supporting information.

Table 1.Crystal data and structure refinement parameters for complexes 1-3 Complex

2

3

Formula

1 C10H6Ag2O9

C10H3Ag3O8

C10H2Ag4O8

Molecular mass

485.89

574.73

681.60

Crystal system Space group

orthorhombic Pca21

monoclinic C2/c

monoclinic P21/n

22.881(5)

29.956(6)

6.6140(13)

6.2606(13)

6.9207(14)

18.941(4)

7.7872(16)

10.373(2)

9.1295(18)

90

90

90

90

104.86(3)

101.85(3)

90

90

90

1115.5(4)

2078.6(7)

1119.4(4)

4

8

4

293

293

293

Dcalc (g·cm )

2.893

3.673

4.044

F(000)

928

2144

1256

Range of h, k, l

Reflections collected

-22 ≤ h ≤ 27 -7 ≤ k ≤ 4 -9 ≤ l ≤ 8 4945

-34 ≤ h ≤ 36 -7 ≤ k ≤ 8 -12 ≤ l ≤ 12 9394

-7 ≤ h ≤ 7 -19 ≤ k ≤ 23 -11 ≤ l ≤ 10 5103

Data/restrain/parameters

1937 / 1 / 152

2037 / 0 / 195

2125 / 0 / 199

Goodness-of-fit on F2

1.143

1.118

1.082

0.0469, 0.0728

0.0264, 0.0431

0.0192, 0.0408

0.0539, 0.0751

0.0319, 0.0447

a (Å) b( Å) c( Å) α (°) β (°) γ (°) V (Å3) Z T, K –3

R1, wR2 [I > 2σ(I)] R1, wR2 (all data)

a

a a

R1 = ∑ ( F0 − FC ) / ∑ F0

wR2 =

[∑ w(F

0

2

− FC

0.0237, 0.0421

) / ∑ w(F ) ]

0.5 2 2

2 2

0

RESULTS AND DISCUSSION

Syntheses and Characterization. Attempts to obtain the products by the reaction of H4btec and Ag(I) metal salts under solution conditions failed due to quick 6


Page 7 of 21 1 2 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


precipitation. Hydrothermal synthesis provides an efficient method for the preparation and crystallization of organic-inorganic materials of the oxide family, and this strategy was adopted for the reaction of H4btec and Ag(I) metal salts in water with NaOH as base. All the three complexes are insoluble in water and common organic solvent. In the three complexes, the Ag(I) metal atoms show different coordination sphere, the H4btec ligands show different deprotonation degree and coordination modes (Scheme 1), and the PXRD are in agreement with simulated pattern from single X-ray diffraction thus confirm pure phase (See Supporting Information). In complex 1, a two-dimensional Ag-O sheet is being observed with the H2btec2- ligands bridge Ag(I) dimers into a three-dimensional framework with the help of hydrogen bonding interactions. As for complex 2, a talon-like Ag(I) hexamer is being observed, which is bridged by the Hbtec3- ligands into a three-dimensional framework. Different from the oligomer Ag(I) in complexes 1 and 2, a one-dimensional Ag(I) chain is obtained with repeat of Ag(I) tetramers as building units in complex 3. The TGA of complexes 1-3 was studied. For the lack of coordination and lattice water molecules in complexes 2 and 3, nearly no weight loss is being observed until 300 oC. In contrast, complex 1 exhibits loss of one coordination water molecule between 30 and 100 °C (3.69% weight loss observed; 3.70% calculated). All these three complexes exhibit sharp weight losses between approximately 300-550 °C (See Supporting Information), followed by slow weight losses.

Scheme 1. Coordination modes of btec exhibit in complexes 1-3. (a) µ7- ŋ1:ŋ1:ŋ0:ŋ1:ŋ2:ŋ2:ŋ0:ŋ0, (b) µ12-ŋ1:ŋ0:ŋ2:ŋ2:ŋ3:ŋ2:ŋ1:ŋ1, (c) µ14-ŋ2:ŋ2:ŋ1:ŋ1:ŋ3:ŋ3:ŋ2:ŋ1.

7



Figure 1. (a) Perspective view of the coordination environment of the Ag(I) atoms in 1. (b) View of the 2D sheet constructed with Ag(I) and O atoms in 1. (c) Hydrogen bonding contributed three-dimensional framework of 1. (d) Perspective view of the (5,7)-connected topology of 1.

Crystal Structures of [Ag2(H2btec)(H2O)] (1). Complex 1 crystallizes in the orthorhombic Pca21 space group with two crystallographically independent Ag(I) atoms, one H2btec2- ligand, and one coordination water molecule. The two crystallographically independent silver(I) atoms show two different coordination sphere. The Ag(1) atom is four coordinated and exhibiting a tetrahedral coordination environment (Fig. 1a). Besides being bonded with three oxygen atoms from three different carboxylate groups provided by three different H2btec2- ligands, the coordination sphere is completed with coordination water molecule, forming a distorted tetrahedral coordination sphere. As for Ag(2), it is five coordinated, besides bonded with four oxygen atoms provided by four H2btec2- ligands, the coordination water molecule completes the coordination sphere and acts as bridging ligands, leading a distorted tetragonal pyramid coordination sphere. The Ag-O distances are in the range of 2.195(5) -2.586(6) Å. On the other hand, the Ag-Ag contacts connect adjacent Ag(1) and Ag(2) into dimer with the distance of 2.8403 Å, which is not only 8


Page 8 of 21

Page 9 of 21 1 2 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


much shorter than twice van der waals radius of the silver(I) ion (3.44 Å), but also shorter than that (2.89 Å) in metal silver, thus suggesting the presence of significant argentophilic interactions.50-52 Those Ag(I) dimers are bridged by coordination water molecules into a one-dimensional chain, which further joined by O5 and O6 into a two-dimensional Ag-O sheet. The H2btec2- ligands connected the Ag-O sheets into a three-dimensional framework. For the existence of abundant carboxylate groups, which could act as hydrogen bonding donor or acceptor, each H2btec2- connects four different H2btec2- via hydrogen bonding interactions (O3···O1 2.526, O8···O5 2.983 Å) (See Supporting Information) and contribute to the crystal packing. From the view of net topology, the silver(I) dimer can be considered as a 7-connected node (purple ball in Fig. 1d) with the bridging water molecules as two-connected spacer, connecting the adjacent silver(I) dimers from either side, while the H2btec2ligand serves as a 5-connected node (gray ball in Fig. 1d). As a result, complex 1 shows

a

3D

(5,7)-connected

framework

with

Schläfli

symbol

of

(3·44·54·6)(32·44·59·65·7) novel topology.

Figure 2. (a) Perspective view of the coordination environments of the Ag(I) atoms in 2. (b) View of the bead-like chain constructed with talon-like hexamers via argentophilic interactions in 2. (c) View of the hydrogen bonding contributed three-dimensional framework of 2. (d) Perspective view of the (5,10)-connected topology of 2.

Crystal Structure of [Ag3(Hbtec)] (2). Complex 2 crystallizes in monoclinic C2/c space group. There are four kinds but three crystallographically independent Ag(I) 9



atoms (two half, two one crystallographically independent Ag(I) atoms), and one Hbtec3- ligand in the asymmetry unit (Fig. 2a). The Ag-O bond lengths are in range of 2.251(3) to 2.513(3) Å in complex 2. The Ag(1) is three coordinated with three oxygen atoms (O1, O3, and O8) from three different Hbtec3- ligands besides one phenyl carbon atom(C4) coordinates to the silver atom Ag(1) with bond length of 2.669 Å, leading a distorted tetrahedral coordination sphere with three oxygen atoms occupy the cone bottom plane and C4 vertex position. The Ag-C bonding is not unusual. References widely reported Ag-C bond lengths in the range of 2.388(5) 2.763(3) Å in Ag(I) polymers for benzene ring C-Ag bonds.53-55 As for Ag(2), it is five coordinated with five oxygen atoms (O3, O5, O5#, O6, O7) from five Hbtec3- ligands forming slight distorted trigonal bipyramid coordination sphere, the O5, O6, O7, and Ag2 are almost coplanar with only 0.0157 Å off the mean plane. The O3 and O5 occupy the two vertex positions of the trigonal bipyramid coordination sphere. As for Ag(3) and Ag(4), both are four coordinated with four oxygen atoms provided by four different Hbtec3- ligands. Differently, the coordination sphere is tetrahedral in Ag(3), while in Ag(4), the Ag4, O4, O6, and O6# are almost coplanar with only 0.0471 Å off the mean plane, forming a T-shape with O6-Ag4-O6# angle of 167.8 °. Notably, the significant argentophilic interactions (Ag-Ag bond lengths 3.0057(8), 3.1538(9), 3.2103(9) Å) aggregate the four different silver(I) atoms into a talon-like Ag(I) hexamer (See Supporting Information). This talon-like hexamer is quite different from the chair-like or benzene-like hexamer reported by Di Sun56 and Antonio Laguna57. Furthermore, a weaker argentophilic interaction (3.3993 Å, See Supporting Information) connected the hexamers into a one-dimensional bead-like Ag(I) chain (Fig. 2b), the weaker interactions is similar to the results reported by Li et al.13 Similar to that of complex 1, the oligomers are being bridged by oxygen atoms into two-dimensional sheets. First the O4 and O4# bridge the hexamers into a one-dimensional chain, the chains were connected with O3, O5, O6, and O8 into the sheet, and the Hbtec3- ligands bridged the sheets into a three-dimensional framework with help of hydrogen bonding interactions (Fig. 2c). 10


Page 10 of 21

Page 11 of 21 1 2 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


From topology view, the Ag(I) hexamer is a ten connected node, while the Hbtec3- is a five connected node. As a result, a 3D (5,10)-connected framework with (410)2(428·616·8) topology being presented and fits MoGe2 type (Fig. 2d).

Figure 3. (a) Perspective view of the coordination environments of the Ag(I) atoms in 3. (b) View of the two-dimensional Ag(I) sheet via argentophilic interactions. (c) Perspective view of the three-dimensional framework in 3. (d) Perspective view of the (8,10)-connected topology of 3.

Crystal Structure of [Ag4(btec)] (3). Complex 3 crystallizes in monoclinic P21/n space group. Despite four kinds Ag(I) atoms display in complex 3 similar to that of complex 2, but four crystallographically independent Ag(I) and one btec4- ligand in the asymmetry unit in 3 (Fig. 3a). The Ag(1) is four coordinated with four oxygen atoms provided by four btec4- ligands, forming a slightly distorted tetrahedral coordination sphere. Differently, the Ag(2) is five coordinated with five oxygen atoms provided by five btec4- ligands, forming a distorted trigonal bipyramid coordination sphere. The O2, O4, O6, and Ag2 are almost coplanar with only 0.0791 Å off the mean plane. The O5 and O7 occupy the two vertex positions of the trigonal bipyramid coordination sphere. Despite both Ag(3) and Ag(4) are three coordinated showing different coordination sphere. In Ag(3) it shows “T” shape, however “Y” shape for Ag(4). Notably, the Ag···Ag distances vary from 2.9344(6) to 3.004(9) Å, those 11



argentophilic interactions bridge the four different silver(I) atoms into a one-dimensional zigzag chain, while the weaker one (3.419(1) and 3.447(1) Å, See Supporting Information) connects the Ag(I) chains into a two dimensional Ag(I) sheet with both 4-numbered and 8-numbered-ring. Each btec4- ligand bridges six Ag(I) chain, and aggregate into a three-dimensional framework (See Supporting Information). From the topological view, we take each Ag(I) tetramer as a building unit, which could be viewed as a ten connected node. Besides being bridged with eight btec4ligands, it bridges with two other tetramers from either side, while the btec4- ligands acts as eight connected node (Fig. 3d). As a result, a 3D framework with (32·423·53)(34·421·519·6) topology displayed in complex 3 (See Supporting Information). In complexes 1-3, the H4btec ligands display different degree of deprotonation (H2btec2- for complexes 1, Hbtec3- for complex 2, and btec4- for complex 3) and coordination modes (See Scheme 1). The different deportation and coordination ability led different argentophilic interactions in three different complexes. A dimer displayed in complex 1, talon-like hexamer in complex 2, while one-dimensional chain built with Ag(I) tetramer in complex 3. Weaker argentophilic interactions connect the talon-like Ag(I) hexamers into a bead-like one-dimensional chain in complex 2, while bridge the tetramer unit chain into a two-dimensional sheet in complex 3. The Ag(I) coordination numbers vary for 3 to 5 in the three different complexes with close bond lengths.

12


Page 12 of 21

Page 13 of 21 1 2 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 4. Emission spectra of free H4btec ligand and complexes 1−3 at room temperature.

Photoluminescent Properties. Emissive coordination compounds are of great current interesting due to their various applications in the areas of chemical sensors and photochemistry. Taking account of the excellent luminescent properties of d10 metal-organic polymers, the solid state photoluminescent properties of complexes 1-3, as well as free H4btec ligand were investigated at room temperature. The emission spectra of free H4btec ligand and complexes 1-3 are shown in Fig.4. The weak emission of free ligand H4btec with energy from 370–550 nm (max = 423 nm) upon excitation at 364 nm, might be assigned to intraligand charge-transfer (LCT).45,58 Excitation of solid samples of complexes 1-3 at λ= 337 nm produce similar intense luminescence at 437, 470 and 550 nm, respectively except intensity. Compared to the photoluminescence spectrum of the free H4btec ligand, the emission bands of complexes 1-3 are more complicated and show significant red-shifted by more than 100 nm. Which might be partially explained by the existence of a shorter Ag-Ag distance in the all three complexes and, thus, leading strong Ag-Ag interactions, which has an important influence on the photoluminescence properties of the argentophilic contacted complexes. The Ag-Ag contacts usually display an important influence on the energy gap between the ground and excited states and do great influence on the photoluminescent properties of complexes.19,59 The similar emissive behaviors may arise from the synergistic effects of different interactions. The emitting states of 1-3 can be tentatively assigned to the ligand-to-metal charge transfer (LMCT) mainly arising from Ag(I)-btec, mixed with metal-centered (d-s/d-p) transitions.20,60 According to the reported literature, with the Ag-Ag interactions increase, energy level of the d-s triplet-cluster-centered (3CC) transition state decrease, making the emission band shift to lower energy.61 As all the three complexes possess strong Ag-Ag interactions and similar emission hebavior, apparently the Ag-Ag interactions display considerable influence. 13



Figure 5. (a) Images of inhibition zones for 1-3 against E. Coli and S. Aureus; (b) Diameters of inhibition zones for 1-3 against E. coli and S. Aureus.

Antibacterial Activities. In order to evaluate the antibacterial activities of complexes 1-3, Gram-negative bacteria, E. coli and Gram-positive bacteria, S. aureus were chosen as model microorganisms, and a series of experiments was implemented. All bacterial routine handling was conducted with Luria Bertani (LB) broth at 37 °C, and long-term storage was performed in glycerol stock stored at −20 °C. The media were made up by dissolving agar and LB broth in distilled water. Zone of inhibition technique was carried out as procedure described by Ning.38,39 Dissolved agar and LB broth mixture was autoclaved for 15 min at 121 °C and then dispensed into sterilized Petri dishes, which is solidified and used for inoculation. Activated strain (50 µL) was placed onto the surface of an agar plate, and spread evenly over the surface by means of a sterile bent glass rod. Then about less than 10 mm diameter of sample was dispersed on the nutrient agar medium. The diameters of inhibition zones were measured by vernier calipers. The zones of inhibition of Ag-based MOFs are shown in Fig.5. Against E. coli, complexes 1-3 exhibit diameters of inhibition zones in 21.0, 16.0, and 18.0 mm, respectively. The diameters of inhibition zones against S. aureus for 1-3 are 19.0, 14.0 and 16.0 mm (Fig.5). The pure ligand has hardly any antibacterial activity with the diameters of inhibition zones being similar to that of filter paper, indicating inactive for the metal-free ligands (See Supporting Information). The Ag(I) complexes show better results than the 11 mm of Ag-NPs, the antibacterial activities of Ag-based 14


Page 14 of 21

Page 15 of 21 1 2 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


MOFs 1-3 are comparable to other reported silver-based MOFs,38,42 suggesting the Ag(I) complexes are potential useful antibacterial material. It is well established that only silver in its ionic or compound forms has antimicrobial activity. Some literature has suggested that the antibacterial property of Ag-based materials arises from the release of Ag+ ions.38,39 The amount of Ag+ releasing into the solution for complexes 1-3 were measured by ICP-AES. Similar to the procedure developed by Ning et al.38 The ground samples of compounds 1–3 were immersed in distilled water in concentrations of 1000 ppm for 5 days. The supernatant fluids were taken to test every 4 h in the first 24 h, after that, it was measured once a day. The Ag+ ion concentrations of the solutions were measured by ICP-AES. As shown in Fig. 6, it was found that the Ag+ release ration showed a significant increase during the first 24 h, and then it kept stable in the subsequent 5 days. When the amounts of the released silver ions were stable, the average concentrations of Ag+ ion in Ag-based MOFs solutions are 27.50 ppm for 1, 19.81 ppm for 2, and 22.12 ppm for 3, respectively. The concentration influence antibacterial properties, leading diameters of inhibition zones for complexes 1–3 are ranked: 1 > 3 > 2.

Figure 6. (a) Concentration of Ag+ ions of 1–3 in aqueous solution within the first 24 h. (b) The average concentration of Ag+ in 1–3 aqueous solution within 5 days.

Compare with other silver-based coordination polymers reported,38,39,44,62 complexes 1–3 have an intermediate rate of Ag+ ions release. This result also indicated that all three compounds could give a steady and prolonged release of Ag+ ions in biocidal concentration, which is higher than commercial Ag-NPs, as reported the Ag-NPs solutions were in the range of 5.685–5.943 ppm.38 15



Based on the experimental results and literature reports, the possible antibacterial mechanism of the silver(I) complexes is to change the potential and concentration of cell environment.38,39,42 The complexes diffused to the bacterial surface and gave sustained release of Ag+, which might change the surrounding of bacterial cell, break the ion balance thus destroy the ion channel, then rupture the cell membrane and cause the death of bacterial. In our experiments, all the silver(I) complexes are stable in water. Soak in water even ultrasonic vibration wash for purification in water did not cause apparent decompose. On the other hand, the light stabilities of the complexes 1-3 were analyzed under UV-vis light at room temperature. Solid ultraviolet visible spectra of complexes 1-3 was tested at 24 h, 48 h, 5d and the powders in dark were also measured as blank, the results indicating the light stability of the three complexes (See Supporting Information). The PXRD patterns of complexes under visible light for two days also imply the framework of complexes is kept. The water and light stability are important characteristics for the further application of the silver(I) complexes in antibacterial agents. From the viewpoint of correlation between structures and properties, the antibacterial activity of 1-3 is closely related to their framework structures. The 1-3 are three-dimensional frameworks, but they crystallize in different space groups with orthorhombic space group Pca21 for 1, monoclinic C2/c for 2 and monoclinic P21/n for 3. The aromatic-carboxylate ligands in 1-3 contain different number of deprotonated carboxyl groups with different coordination modes, respectively, and they combine with Ag(I) atoms to form different building blocks. Importantly, these frameworks have discriminating capacities to release Ag+ ions (Fig.6), which lead to the different antimicrobial activities correspondingly (Fig.5). Interestingly, the complex 1 has less silver(I) composite but displaying the best antibacterial activity. Many factors could influence on the metal ion release, which including crystal morphologies, composition and framework.39,62 On the other hand, both Ag–O coordination bonding and Ag-Ag interactions could do great influence on the Ag+ release.42, 43The average Ag-O lengths for complexes 1-3 are 2.431, 2.378, 16


Page 16 of 21

Page 17 of 21 1 2 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


and 2.363 Å, respectively. The complex 1 has slighter weaker Ag-O bonds, maybe account for the best activity. Complex 2 and 3 possess silver(I) chain and sheet rather than simple oligomer. Besides, Ag-O bonds, complex 2 also possess Ag-C bonding, which may also increase the stability. As for Ag-Ag interactions, complex 2 and 3 possess silver(I) chain and sheet, respectively. While only simple dimer in complex 1, the complicated Ag-Ag interactions bonding in the complexes 2 and 3, may contribute low Ag+ release despite they possess more silver number.43 The reason for the different Ag+ release and antibacterial activity of the complexes still need system work being carried out. CONCLUSIONS In summary, we successfully construct three Ag(I) coordination complexes based on H4btec with different deprotonation degree thus different coordination mode. Interesting Ag-Ag interactions appeared in the three different complexes. In 1, an Ag dimer demonstrated with strong argentophilic interactions similar to the silver metal. Howerer, a novel talon-like hexamer appeared in complex 2, which bridged by weaker argentophilic interactions into one-dimensional bead-like chain. While in complex 3, the four different crystallographically independent silver(I) atoms aggregate into one-dimensional chain, and the chains are connected by very weak argentophilic interactions into a two-dimensional sheet. The photoluminescent properties were also investigated in the solid state at room temperature. The results show that the argentophilic interactions do great influence on the photoluminescent properties. These materials can regulate the sustained release of silver ions leading to excellent antibacterial activities towards both Gram-negative bacteria, E. coli and Gram-positive bacteria, S. aureus. ACKNOWLEDGMENTS This work was financially supported by the National Natural Science Foundation of China (No. 21171075), and Start-up Fund for Advanced Professional of Jiangsu University (No. 08JDG031). ASSOCIATED CONTENT Supporting Information 17



Page 18 of 21

The Supporting Information is available free of charge via the Internet at http://pubs.acs.org. Accession Codes CCDC 1547084-1547086 contains the supplementary crystallographic data for this paper.

These

data

can

be

obtained

http://www.ccdc.cam.ac.uk/conts/retrieving.html,

free or

of

from

charge the

via

Cambridge

Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: (+44) 1223-336-033; or e-mail: [email protected]. AUTHOR INFORMATION Corresponding Author *E-mail:[email protected]. Fax: (+86)-511-88791800. Tel: (+86)-511-88791708. Notes The authors declare no competing financial interest.

References (1) Lin, Z. J.; Lu, J.; Hong, M.; Cao, R., Chem. Soc. Rev. 2014, 43, 5867-5895. (2) Chughtai, A. H.; Ahmad, N.; Younus, H. A.; Laypkov, A.; Verpoort, F., Chem. Soc. Rev. 2015, 44, 6804-6849. (3) Schoedel, A.; Li, M.; Li, D.; O'Keeffe, M.; Yaghi, O. M., Chem. Rev. 2016, 116, 12466-12535. (4) Yang, Y.; Jiang, F.; Liu, C.; Chen, L.; Gai, Y.; Pang, J.; Su, K.; Wan, X.; Hong, M., Cryst. Growth Des. 2016, 16, 2266-2276. (5) Singh, D.; Nagaraja, C. M., Cryst. Growth Des. 2015, 15, 3356-3365. (6) Li, B.; Zhang, Y.; Ma, D.; Ma, T.; Shi, Z.; Ma, S., J. Am. Chem. Soc. 2014, 136, 1202-1205. (7) Jeong, S.; Kim, D.; Shin, S.; Moon, D.; Cho, S. J.; Lah, M. S., Chem. Mater. 2014, 26, 1711-1719. (8) Hui, A. K.; Losovyj, Y.; Lord, R. L.; Caulton, K. G., Inorg. Chem. 2014, 53, 3039-3047. (9) Yadav, P. K.; Kumari, N.; Pachfule, P.; Banerjee, R.; Mishra, L., Cryst. Growth Des.2012, 12, 5311-5319. (10) Chen, Q.; Xue, W.; Lin, J. B.; Lin, R. B.; Zeng, M. H.; Chen, X. M., Dalton Trans. 2012, 41, 4199-4206. (11) Zha, Q.; Rui, X.; Wei, T.; Xie, Y., CrystEngComm 2014, 16, 7371-7384. (12) Huang, Y.; Song, Y.-S.; Yan, B.; Shao, M., J. Solid State Chem. 2008, 181, 1731-1737. (13) Li, B.; Zang, S. Q.; Ji, C.; Du, C. X.; Hou, H. W.; Mak, T. C., Dalton Trans. 2011, 40, 788-792. (14) Sun, D.; Yan, Z.-H.; Liu, M.; Xie, H.; Yuan, S.; Lu, H.; Feng, S.; Sun, D., Cryst. Growth Des. 2012, 12, 2902-2907. 18


Page 19 of 21 1 2 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


(15) Wang, L.-M.; Wang, Y.; Fan, Y.; Xiao, L.-N.; Hu, Y.-Y.; Gao, Z.-M.; Zheng, D.-F.; Cui, X.-B.; Xu, J.-Q., CrystEngComm 2014, 16, 430-440. (16) Han, L.-L.; Zhang, X.-Y.; Chen, J.-S.; Li, Z.-H.; Sun, D.-F.; Wang, X.-P.; Sun, D., Cryst. Growth Des. 2014, 14, 2230-2239. (17) Shi, H.-Y.; Dong, Y.-B.; Liu, Y.-Y.; Ma, J.-F., CrystEngComm 2014, 16, 5110-5120. (18) Wang, H.; Wan, C. Q.; Mak, T. C., Dalton Trans. 2014, 43, 7254-7262. (19) Wang, Z.-H.; Wang, D.-F.; Zhang, T.; Huang, R.-B.; Zheng, L.-S., CrystEngComm 2014, 16, 5028-5039. (20) Li, B.; Zang, S. Q.; Ji, C.; Liang, R.; Hou, H. W.; Wu, Y. J.; Mak, T. C., Dalton Trans. 2011, 40, 10071-1081. (21) Li, B.; Zang, S.-Q.; Liang, R.; Wu, Y.-J.; Mak, T. C. W., Organometallics 2011, 30, 1710-1718. (22) Li, B.; Ji, C.; Zang, S. Q.; Hou, H. W.; Mak, T. C., Dalton Trans. 2012, 41, 9151-9153. (23) Li, B.; Zang, S.-Q.; Ji, C.; Hou, H.-W.; Mak, T. C. W., Cryst. Growth Des. 2012, 12, 1443-1451. (24) Li, B.; Zang, S.-Q.; Li, H.-Y.; Wu, Y.-J.; Mak, T. C. W., J. Organomet. Chem. 2012, 708-709, 112-117. (25) Zhang, Z.-J.; Liu, H.-Y.; Zhang, S.-Y.; Shi, W.; Cheng, P., Inorg. Chem. Commun. 2009, 12, 223-226. (26) Hao, H.-J.; Sun, D.; Li, Y.-H.; Liu, F.-J.; Huang, R.-B.; Zheng, L.-S., Cryst. Growth Des.2011, 11, 3564-3578. (27) Sun, D.; Zhang, N.; Huang, R.-B.; Zheng, L.-S., Cryst. Growth Des. 2010, 10, 3699-3709. (28) Li, C.-P.; Chen, J.; Yu, Q.; Du, M., Cryst. Growth Des. 2010, 10, 1623-1632. (29) Zhang, Z.; Ma, J.-F.; Liu, Y.-Y.; Kan, W.-Q.; Yang, J., Cryst. Growth Des. 2013, 13, 4338-4348. (30) Duan, X.-Y.; Yao, J.; Lu, C.-S.; Meng, Q.-J., J. Solid State Chem. 2013, 200, 197-201. (31) Huang, R.-W.; Zhu, Y.; Zang, S.-Q.; Zhang, M.-L., Inorg. Chem. Commun. 2013, 33, 38-42. (32) Sun, D.; Cao, R.; Weng, J.; Hong, M.; Liang, Y., Dalton Trans. 2002, 291-292. (33) Wang, D.-f.; Wang, Z.-h.; Zhang, T.; Dai, S.-m.; Huang, R.-B.; Zheng, L.-S., Inorg. Chim. Acta 2014, 415, 61-68. (34) Sun, D.; Zhang, N.; Luo, G.-G.; Xu, Q.-J.; Huang, R.-B.; Zheng, L.-S., Polyhedron 2010, 29, 1842-1848. (35) Cheng, X.; Liu, T.; Duan, X.; Wang, F.; Meng, Q.; Lu, C., CrystEngComm 2011, 13, 1314-1321. (36) Alisir, S. H.; Demir, S.; Sariboga, B.; Buyukgungor, O., J. Coord. Chem. 2015, 68, 155-168. (37) Medici, S.; Peana, M.; Crisponi, G.; Nurchi, V. M.; Lachowicz, J. I.; Remelli, M.; Zoroddu, M. A., 2016, 327-328, 349-359. (38) Lu, X.; Ye, J.; Sun, Y.; Bogale, R. F.; Zhao, L.; Tian, P.; Ning, G., Dalton Trans. 2014, 43, 10104-10113. (39) Lu, X.; Ye, J.; Zhang, D.; Xie, R.; Bogale, R. F.; Sun, Y.; Zhao, L.; Zhao, Q.; Ning, G., J. Inorg. Biochem. 2014, 138, 114-121. (40) Qin, L.; Wang, P.; Guo, Y.; Chen, C.; Liu, M., Adv. Sci. 2015, 2, 1500134-1500140. (41) Cheng, H.; Ye, J.; Sun, Y.; Yuan, W.; Tian, J.; Bogale, R. F.; Tian, P.; Ning, G., RSC Adv. 2015, 5, 80668-80676. (42) Chen, S. C.; Zhang, Z. H.; Chen, Q.; Wang, L. Q.; Xu, J.; He, M. Y.; Du, M.; Yang, X. P.; Jones, R. A., Chem. Commun 2013, 49, 1270-1272. (43) Haziz, U. F. M.; Haque, R. A.; Amirul, A. A.; Shaheeda, N.; Razali, M. R., Polyhedron 2016, 117, 628-636. 19



(44) Fiori, A. T. M.; Nakahata, D. H.; Cuin, A.; Lustri, W. R.; Corbi, P. P., Polyhedron 2017, 121, 172-179. (45) Xia, C.-K.; Wu, F.; Yang, K.; Wu, Y.-L.; Lu, X.-J., Polyhedron 2016, 112, 78-85. (46) Xia, C.-K.; Wu, F.; Yang, K.; Sun, W.; Min, Y.-Y.; Wu, Y.-L.; Lu, X.-J., Polyhedron 2016, 117, 637-643. (47) Wei, C.; Xia, C.-K.; Wu, Y.-L.; Wu, F.; Yang, S.; Ma, J.-L., Polyhedron 2015, 89, 189-195. (48) Sheldrick, G. M., SADABS, Program for Empirical Absorption Correction of Area Detector Data, University of Göttingen, Germany, 2014. (49) Sheldrick, G. M., SHELXS-2014, Program for Crystal Structure Solution, Gottingen University, Göttingen, Germany, 2014. (50) Schmidbaur, H.; Schier, A., Angew. Chem. Int. Ed. 2015, 54, 746-784. (51) Fernández, E. J.; López-de-Luzuriaga, J. M.; Monge, M.; Rodríguez, M. A.; Crespo, O.; Gimeno, M. C.; Laguna, A.; Jones, P. G., Inorg. Chem. 1998, 37, 6002-6006. (52) Assefa, Z.; Shankle, G.; Patterson, H. H.; Reynolds, R., Inorg. Chem. 1994, 33, 2187-2195. (53) Deng, Z.-P.; Li, M.-S.; Zhu, Z.-B.; Huo, L.-H.; Zhao, H.; Gao, S., Organometallics 2011, 30, 1961-1967. (54) Sun, D.; Zhang, N.; Xu, Q.-J.; Huang, R.-B.; Zheng, L.-S., J. Organomet. Chem. 2010, 695, 1598-1602. (55) Yilmaz, V. T.; Soyer, E.; Buyukgungor, O., J. Organomet. Chem. 2009, 694, 3306-3311. (56) Sun, D.; Luo, G.-G.; Zhang, N.; Xu, Q.-J.; Yang, C.-F.; Wei, Z.-H.; Jin, Y.-C.; Lin, L.-R.; Huang, R.-B.; Zheng, L.-S., Inorg. Chem. Commun. 2010, 13, 290-293. (57) Barreiro, E.; Casas, J. S.; Couce, M. D.; Laguna, A.; López-de-Luzuriaga, J. M.; Monge, M.; Sánchez, A.; Sordo, J.; Vázquez López, E. M., Dalton Trans. 2013, 42, 5916-5923. (58) Allendorf, M. D.; Bauer, C. A.; Bhakta, R. K.; Houk, R. J., Chem. Soc. Rev. 2009, 38, 1330-1352. (59) Sun, D.; Liu, F.-J.; Huang, R.-B.; Zheng, L.-S., CrystEngComm 2013, 15, 1185-1193. (60) Zhu, J. J.; Hu, P.; Zhou, K. K.; Li, B.; Zhang, T., Dalton Trans. 2017, 46, 6663-6669. (61) Yan, Z. H.; Li, X. Y.; Liu, L. W.; Yu, S. Q.; Wang, X. P.; Sun, D., Inorg. Chem. 2016, 55, 1096-1101. (62) Chevrier, I.; Sague, J. L.; Brunetto, P. S.; Khanna, N.; Rajacic, Z.; Fromm, K. M., Dalton Trans. 2013, 42, 217-231.

20


Page 20 of 21

Page 21 of 21 1 2 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


For Table of Contents Use Only

Syntheses, Crystal Structures and Properties of Three Novel Silver-Organic Frameworks Assembled from 1,2,3,5-Benzenetetracarboxylic Acid Based on Argentophilic Interactions Chang-Kun Xia,* Yuan-Yuan Min, Kai Yang, Wen Sun, De-Li Jiang, Min Chen

Three novel silver(I) metal-organic coordination polymers were constructed with adjacent dense polycarboxylate ligand as building block; their structural, topological, luminescent properties, and antibacterial activities are discussed.

21


Syntheses, Crystal Structures, and Properties of Three Novel Silver

Recommend Documents