Structural Systematics and Topological Analysis of Coordination

Article pubs.acs.org/crystal

Structural Systematics and Topological Analysis of Coordination Polymers with Divalent Metals and a Glycine-Derived Tripodal Phosphonocarboxylate Konstantinos D. Demadis,*,† Eirini Armakola,† Konstantinos E. Papathanasiou,† Gellert Mezei,*,‡ and Alexander M. Kirillov§ †

Crystal Engineering, Growth and Design Laboratory, Department of Chemistry, University of Crete, Voutes Campus, Heraklion, Crete, GR-71003, Greece ‡ Department of Chemistry, Western Michigan University, Kalamazoo, Michigan 49008-5413, United States § Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais, 1049-001, Lisbon, Portugal S Supporting Information *

ABSTRACT: A novel family of four hybrid metal phosphonate coordination polymers is reported that are constructed from divalent metal ions (Ca, Sr, Ba, and Pb) and BPMGLY (bisphosphonomethylglycine, a phosphonated derivative of glycine). These compounds (and their compositions) are Ca-BPMGLY (CaBPMGLY·H2O), Sr-BPMGLY (SrBPMGLY·H2O), Ba-BPMGLY (Ba3.5(BPMGLY)2·6H2O), and Pb-BPMGLY (PbBPMGLY·H2O). They were obtained by hydrothermal reactions in acidic aqueous solutions (pH range 2.3−5.7) and fully characterized by physicochemical methods and structural analysis. Ca-BPMGLY, Sr-BPMGLY, and Pb-BPMGLY have very similar 3D coordination polymer structures, and the latter two are isostructural. In contrast to the Ca, Sr, and Pb analogs, Ba-BPMGLY possesses a different 2D layered network. These four new compounds, together with our previously reported 2D coordination polymer Mg-BPMGLY (MgBPMGLY·2H2O, Demadis et al. Inorg. Chem. 2012, 51, 7889−7896), were topologically classified revealing (i) the uninodal 3-connected net with the hcb topology in Mg-BPMGLY, (ii) the uninodal 5-connected nets with the bnn and vbj topology in Ca-BPMGLY and Sr-BPMGLY, respectively, and (iii) the very complex topologically unique hexanodal 4,4,6,6,7,8-connected net in Ba-BPMGLY. The vbj topology was also identified in the related Pb-BPMGLY 3D framework. These topological features show that the complexity of BPMGLY-driven 2D and 3D metal−organic networks increases periodically following the Mg < Ca ≤ Sr ≪ Ba trend.

■

INTRODUCTION The research of metal phosphonate hybrid compounds has emerged as a rapidly growing field of inorganic and materials chemistry. The latest advances in this area have been recently presented in a comprehensive way in a book.1 In addition, several detailed review articles have appeared that summarize the essence of metal phosphonate chemistry.2 (Poly)phosphonic acids play a key role in the advancement of synthetic metal phosphonate chemistry. Since the first synthesis by Alberti in 1978 (hydrothermal treatment for 30 days at 190−200 °C in the presence of HF),3 and structural characterization of the first metal phosphonate compound (Zirconium(IV) phenylphosphonate, Zr(O3PPh)2) by Clearfield in 1993 (from powder data),4 there has been an admirable plethora of various phosphonic acid linkers, thanks to advancements in phosphorus chemistry.5 Nowadays there are several research groups that pursue elegant synthetic methodologies that have yielded an astonishing structural variability of phosphonate ligands (polyphosphonates,6 carboxyphosphonates, 7 sulfonophosphonates, 8 aromatic phosphonates,9 heterocycle-bearing phosphonates,10 etc.). All © 2014 American Chemical Society

these new phosphonate linker structures have enriched the inorganic/coordination chemist’s “ligand toolbox”, thus enabling access to new phosphonate metal−organic framework (MOF) structure types. In contrast to the well-established and (to an extent) predictable MOF structures based on carboxylate linkers, metal phosphonate MOFs are almost impossible to predict. Hence, the concept of “isoreticular” metal phosphonate chemistry is at its infancy. A notable example of structural unpredictability originates from our past work on alkaline-earth metal AMP compounds (AMP = amino-tris(methylenephosphonate)). Under identical synthetic conditions the four alkaline-earth metal ions Mg2+ (1D), Ca2+ (2D), Sr2+ (2D pillared), and Ba2+ (3D) yield four different structure types.11 However, there are notable exceptions.12,13 Whenever possible, there are strategies available and efforts implemented to systematize ligand behavior, which will ideally lead to materials design and structure prediction. Received: July 9, 2014 Revised: August 5, 2014 Published: August 13, 2014 5234

dx.doi.org/10.1021/cg501029b | Cryst. Growth Des. 2014, 14, 5234−5243

Crystal Growth & Design

Article

Ca-BPMGLY. The compound was synthesized under hydrothermal conditions, as follows. A mixture of CaCl2·2H2O (0.0147 g, 0.1 mmol) and BPMGLY (0.0263 g, 0.1 mmol) were dissolved in 3 mL of DI water. The pH was adjusted to 2.3 with HCl and NaOH stock solutions. The clear, colorless solution was placed into a sealed custom-made bomb equipped with a Teflon liner and then heated at 140 °C for 3 days. After the solution was slowly cooled to room temperature, colorless crystals were isolated by filtration. Sr-BPMGLY. The compound was synthesized in the same manner as Ca-BPMGLY. SrCl2·6H2O (0.0267 g, 0.1 mmol) and BPMGLY (0.0263 g, 0.1 mmol) were used, and the pH was adjusted to 3.0. Ba-BPMGLY. The compound was synthesized in the same manner as Ca-BPMGLY. BaCl2·2H2O (0.0733 g, 0.3 mmol) and BPMGLY (0.0789 g, 0.3 mmol) were used, and the pH was adjusted to 4.2. Pb-BPMGLY. The compound can be synthesized under either ambient or hydrothermal conditions (140 °C for 3 days). The hydrothermal synthesis yields a microcrystalline powder, whereas the room temperature synthesis affords single crystals. Hence, we present the latter. A quantity of Pb(NO3)2 (0.0994 g, 0.3 mmol) and BPMGLY (0.0789 g, 0.3 mmol) were dissolved in 15 mL of deionized water. The final pH was adjusted to 1.4. Then this solution was covered with parafilm, some holes were poked in the parafilm, and it was left undisturbed for 7 days at room temperature. Colorless crystals formed, and they were isolated by filtration, washed with small amounts of DI water, and air dried. X-ray Crystallography. X-ray diffraction data were collected at room temperature from a single-crystal mounted atop a glass fiber under Paratone-N oil, with a Bruker SMART APEX II diffractometer using graphite-monochromated Mo Kα (λ = 0.71073 Å) radiation. The structures were solved by employing SHELXTL direct methods and refined by full-matrix least-squares on F2, using the APEX2, version 2013.4-1 software package.19 All non-H atoms were refined with independent anisotropic displacement parameters. Hydrogen atoms were placed at calculated positions and refined using a riding model, except for the water, phosphonic acid, and NH+ hydrogens, which were located from the Fourier difference density maps and refined using a riding model with O−H and N−H distance restraints. Crystallographic details are summarized in Table 1. Important bond distances are given in Table 2 and hydrogen bonding details are shown in Table 3.

Aminomethylene phosphonates are an interesting class of phosphonate linkers that possess the −N−CH2−PO3H2 moiety. Apart from their particular structural features (e.g., the N atom is almost always found protonated14) and the easy synthetic access,15 they have drawn interest because of their potential use in medicinal applications.16 As mentioned above, the phosphonate moiety can coexist with other functional groups on the same ligand backbone. Hence, carboxyphosphonates constitute an interesting class of ligands. In this context, BPMGLY (bis-phosphonomethylglycine, a phosphonated derivative of glycine) is a carboxy-bis-phosphonate tripodal ligand that combines one −COOH and two −PO3H2 moieties. BPMGLY could be envisioned as a member of a family of tridentate ligands originating from NTA (nitrilo-triacetate) by systematically “replacing” carboxylate moieties by phosphonate ones. In this way, the resulting ligands are PMIDA, BPMGLY, and AMP. These systematic structural changes are shown in Figure 1.

■

RESULTS AND DISCUSSION Syntheses. The BPMGLY ligand exists as a zwitterion in the absence of externally added base, as one of the phosphonic acid groups internally protonates the N atom. It can potentially acquire a “5−” charge, with both phosphonic acid and the carboxylic acid groups completely deprotonated.20 This can only be achieved at pH > 10, where the N is also deprotonated. However, at the synthesis pH values, the ligand carries a “2−” charge: the carboxylic acid group is deprotonated (COO−), the two phosphonic acid groups are singly deprotonated (PO3H−), and the N atom is protonated (NH+). Mildly acidic pH values ( 2σ(I)] data/restraints/params GOF (on F2) R factor [I > 2σ(I)] R factor (all data) max peak/hole (e·Å−3) CCDC number

CaBPMGLY·H2O

SrBPMGLY·H2O

Ba3.5(BPMGLY)2·6H2O

PbBPMGLY·H2O

C4H11CaNO9P2 319.16 triclinic P1̅ 7.1200(4) 7.2986(5) 10.5043(6) 78.615(5) 80.272(5) 88.585(5) 527.41(6) 0.01 × 0.02 × 0.30 2 2.010 0.939 2.01−26.02 11139 1622 2074/5/169 1.057 R1 = 0.0417 wR2 = 0.0963 R1 = 0.0600 wR2 = 0.1056 0.575/−0.439 1008488

C4H11NO9P2Sr 366.70 monoclinic P21/c 7.3371(2) 7.5180(2) 20.5697(5) 90.000 100.074(1) 90.000 1117.14(5) 0.10 × 0.12 × 0.30 4 2.180 5.151 2.01−34.60 36147 3692 4481/4/166 1.016 R1 = 0.0270 wR2 = 0.0525 R1 = 0.0406 wR2 = 0.0559 0.617/−0.588 1008489

C8H18Ba3.5N2O22P4 1098.81 triclinic P1̅ 9.3466(2) 12.7982(3) 13.2133(3) 67.255(1) 74.391(1) 86.595(1) 1402.13(6) 0.01 × 0.12 × 0.38 2 2.603 5.174 1.73−30.56 79726 7270 8547/10/411 1.007 R1 = 0.0242 wR2 = 0.0549 R1 = 0.0329 wR2 = 0.0588 0.786/−0.860 1008490

C4H11NO9P2Pb 486.27 monoclinic P21/c 7.3135(2) 7.6312(2) 20.5697(5) 90.000 99.462(1) 90.000 1132.39(5) 0.10 × 0.15 × 0.23 4 2.852 15.219 2.01−36.31 53683 4668 5504/4/166 1.057 R1 = 0.0222 wR2 = 0.0414 R1 = 0.0313 wR2 = 0.0435 0.786/−1.462 1008491

Table 2. Selected Bond Distances (Å) for the Reported Materials CaBPMGLY·H2O Ca1−O1 Ca1−O2 Ca1−O3

2.404(2) 2.421(2) 2.576(2)

Ca1−O4 Ca1−O6 Ca1−O7

2.368(2) 2.301(2) 2.541(2)

Ca1−O9 2.359(3) P1−O1 1.493(2) P1−O2 1.496(2) SrBPMGLY·H2O

P1−O3 P2−O4 P2−O5

1.574(2) 1.507(2) 1.562(3)

P2−O6 C4−O7 C4−O8

1.490(2) 1.234(4) 1.270(4)

Sr1−O1 Sr1−O2 Sr1−O3

2.476(1) 2.565(1) 2.681(1)

Sr1−O4 Sr1−O6 Sr1−O7

2.522(1) 2.447(1) 2.660(1)

Sr1−O9 2.514(1) P1−O1 1.487(1) P1−O2 1.500(1) Ba3.5(BPMGLY)2·6H2O

P1−O3 P2−O4 P2−O5

1.577(1) 1.505(1) 1.571(1)

P2−O6 O7−C4 O8−C4

1.488(1) 1.237(2) 1.266(2)

Ba1−O1 Ba1−O4 Ba1−O9 Ba1−O11 Ba1−O12 Ba1−O13 Ba1−O17 Ba1−O18 Ba2−O2 Ba2−O5

2.971(2) 2.686(2) 2.699(2) 2.727(2) 2.851(2) 2.676(2) 2.901(2) 2.766(3) 2.656(2) 2.669(2)

Ba2−O5′ Ba2−O6 Ba2−O9 Ba2−O10 Ba2−O15 Ba2−O16 Ba2−O17 Ba3−O2 Ba3−O4 Ba3−O6

2.741(2) 2.969(2) 2.722(2) 3.076(3) 2.959(2) 2.910(2) 2.872(3) 2.845(2) 2.888(2) 2.744(2)

Ba3−O6′ 2.758(2) Ba3−O7 2.654(2) Ba3−O10 2.682(2) Ba3−O12 2.784(2) Ba3−O15 2.775(2) Ba4−O1′ 2.681(2) Ba4−O1 2.681(2) Ba4−O11 2.660(2) Ba4−O11′ 2.660(2) Ba4−O12 2.894(2) PbBPMGLY·H2O

Ba4−O12′ P1−O1 P1−O2 P1−O3 P2−O4 P2−O5 P2−O6 P3−O9 P3−O10 P3−O11

2.894(2) 1.504(2) 1.509(2) 1.543(2) 1.511(2) 1.513(2) 1.526(2) 1.526(2) 1.509(2) 1.510(2)

P4−O12 P4−O13 P4−O14 C4−O7 C4−O8 C8−O15 C8−O16

1.514(2) 1.486(2) 1.541(2) 1.241(4) 1.225(4) 1.254(4) 1.245(4)

Pb1−O1 Pb1−O2 Pb1−O3

2.364(2) 2.678(2) 2.957(2)

Pb1−O4 Pb1−O6 Pb1−O7

2.649 (2) 2.381(2) 2.816(2)

P1−O3 P2−O4 P2−O5

1.567(2) 1.501(2) 1.566(2)

P2−O6 C4−O7 C4−O8

1.491(2) 1.226(3) 1.272(3)

Pb1−O9 P1−O1 P1−O2

2.441(2) 1.491(2) 1.497(2)

In the case of SrBPMGLY·H2O, the water molecule is removed between ∼175−225 °C (calcd 4.9%, obsd 5.0%), and decomposition starts at ∼300 °C. PbBPMGLY·H2O begins to lose the water molecule at ∼145 °C (calcd 3.7%), and starts decomposing at ∼200 °C, before the whole amount of water is eliminated. In the case of Ba3.5(BPMGLY)2·6H2O, removal of water starts immediately upon heating: the first, second, and

All products were monophasic based on comparisons of the calculated and measured XRD powder patterns (see Supporting Information). Thermogravimetric Analysis (TGA). TGA (Figure 2) indicates that the water molecule of CaBPMGLY·H2O is lost between ∼130−220 °C (calcd 5.6%, obsd 5.5%), and decomposition of the anhydrous complex starts at ∼310 °C. 5236



Article

Table 3. Summary of Hydrogen Bonding Data for the Reported Materials compound CaBPMGLY·H2O

SrBPMGLY·H2O

Ba3.5(BPMGLY)2·6H2O

PbBPMGLY·H2O

D−H···A

D−H (Å)

H···A (Å)

D···A (Å)

D−H−A (deg)

O9−H9A···O4 O9−H9B···O8 O3−H3···O8 O5−H5···O2 N1−H1···O1 N1−H1···O4 O9−H9A···O4 O9−H9B···O8 O3−H3···O8 O5−H5···O2 N1−H1···O1 N1−H1···O4 O17−H17A···O3 O17−H17B···O20 O18−H18A···O21A O18−H18A···O21B O18−H18B···O22 O20−H20A···O21A O20−H20B···O16 O22−H22A···O3 O22−H22B···O20 O14−H14···O3 N1−H1···O2 N2−H2···O9 N2−H2···O15 O9−H9A···O4 O9−H9B···O8 O3−H3···O8 O5−H5···O2 N1−H1···O1 N1−H1···O4

0.83(2) 0.79(2) 0.82(2) 0.82(2) 0.89(2) 0.89(2) 0.80(2) 0.80(2) 0.82(2) 0.82(2) 0.88(2) 0.88(2) 0.80(2) 0.81(2) 0.82(2) 0.82(2) 0.81(2) 0.84(2) 0.85(2) 0.82(2) 0.84(2) 0.83(2) 0.89(2) 0.88(2) 0.88(2) 0.82(2) 0.80(2) 0.81(2) 0.81(2) 0.90(2) 0.90(2)

2.05(2) 1.96(2) 1.68(2) 1.80(2) 2.46(3) 2.57(3) 2.01(2) 2.04(2) 1.69(2) 1.78(2) 2.36(2) 2.53(2) 2.04(2) 2.18(2) 2.21(3) 1.86(3) 1.97(2) 2.32(6) 1.87(3) 2.32(5) 2.19(5) 1.67(2) 2.07(3) 2.12(3) 2.18(3) 1.92(2) 1.99(2) 1.70(2) 1.76(2) 2.36(3) 2.43(3)

2.842(4) 2.753(3) 2.494(3) 2.615(3) 2.998(3) 3.035(3) 2.803(2) 2.832(2) 2.498(2) 2.594(2) 2.925(2) 3.044(2) 2.828(3) 2.942(5) 3.02(12) 2.66(2) 2.769(5) 2.91(2) 2.677(5) 2.996(5) 2.825(6) 2.494(3) 2.745(3) 2.762(3) 2.659(3) 2.730(3) 2.791(3) 2.503(3) 2.568(3) 2.940(3) 2.996(3)

162(5) 179(5) 172(4) 174(4) 120(3) 114(3) 173(3) 178(3) 171(2) 177(2) 122(2) 118(2) 166(5) 157(4) 170(5) 164(6) 171(6) 128(6) 157(6) 140(6) 133(6) 173(5) 131(3) 130(3) 114(3) 170(4) 177(5) 168(4) 176(4) 122(2) 121(2)

symmetry operator for A −x −x −x −x

+ + + +

1, 1, 1, 1,

−y, −z + 1 −y + 1, −z + 1 −y + 1, −z + 1 −y, −z + 2

−x −x −x −x

+ + + +

1, 1, 1, 1,

−y + 2, −z + 1 −y + 1, −z + 1 −y + 1, −z + 1 y + 1/2, −z + 1/2

x − 1, y, z −x + 1, −y + 1, −z + 1 x, y + 1, z x, y + 1, z x, y + 1, z x, y, z + 1 x + 1, y, z −x + 1, −y + 1, −z x − 1, y, z − 1 −x + 1, −y + 2, −z + 1

−x −x −x −x

+ + + +

1, 1, 1, 1,

−y + 2, −z −y + 1, −z −y + 1, −z y + 1/2, −z + 1/2

Figure 2. TGA curves for the four compounds studied.

third H2O molecules are lost by 50, 80, and 90 °C, respectively. The remaining three H2O molecules are lost slowly between ∼90−380 °C (calcd 9.8%, obsd 10.6%), followed by sudden decomposition at ∼380 °C. FT-IR Studies. The relevant spectral regions are shown in Figure 3. All compounds show a weak and broad peak at ∼2300 cm−1, which is assigned to the N−H+ moiety. The range 900−1200 cm−1 is a complex spectral region characteristic of vibrations related to the −PO3 moiety (Figure 3, right). It is a useful “fingerprint” region, but challenging to fully assign. There are certain similarities between the Ca and Sr compounds, as they are isostructural.

Figure 3. ATR-IR spectra of the four reported compounds. Two regions are shown: (left) carboxylate region, (right) phosphonate region. Color codes: free ligand BPMGLY (black), Ca-BPMGLY (red), Sr-BPMGLY (blue), Ba-BPMGLY (green), and Pb-BPMGLY (orange).

The vibrations related to the carboxylate group also give information on its binding mode (Figure 3, left). The ν(CO)asym stretch for “free” BPMGLY appears as a sharp narrow band at 1728 cm−1, as expected for a free carboxylic acid moiety. For comparison, the ν(CO)asym stretch for hydroxyphosphonoacetic acid (HPAA) appears at 1734 cm−1.21 Upon coordination to the metal center the ν(CO)asym stretch shifts to lower frequencies, 5237



Article

namely, 1578 (Ca), 1618 (Sr), 1598 (Ba), and 1572 (Pb) cm−1. In the cases of the Ca, Sr, and Ba derivatives the uncoordinated carbonyl oxygen is hydrogen-bonded to a metal-coordinated water molecule. This is a reason for ν(CO)asym peak broadening. In the Pb compound, the uncoordinated carbonyl oxygen is simultaneously hydrogen-bonded to a metalcoordinated water molecule and a −P−OH moiety (from a neighboring BPMGLY ligand). Scanning Electron Microscopy studies. It is well-known that solution pH can profoundly influence the outcome of a synthetic process, especially when pH-sensitive reagents are involved.22 A SEM study was performed on crystalline CaBPMGLY products isolated at five pH values 2.3, 3.1, 3.9, 4.7, and 5.7. The results are shown in Figure 4 in two

coordination polymer structures, and the latter two are isostructural. In all three structures, the BPMGLY ligand carries a 2− charge: the carboxylic acid group is deprotonated (−COO−), the two phosphonic acid groups are singly deprotonated (−PO3H−), and the N atom is protonated (−NH+). All ligand O atoms are coordinated to the metal except one carboxylate and one protonated phosphonate O atom. The metal cations are 7-coordinate with approximately pentagonalbipyramidal geometries, with two axial phosphonate O atoms, two equatorial phosphonate O atoms, one equatorial water O atom, one equatorial protonated phosphonate O atom and one equatorial carboxylate O atom. In each structure, the latter two bonds (M−O3 and M−O7) are longer than the other five bonds (Table 2). In the case of the Pb-BPMGLY structure those two bonds are markedly longer, due to the stereochemically active lone pair on the Pb atom. The H2O, −PO3H−, and −NH+ H atoms form hydrogen bonds to adjacent O atoms (Table 3). Structural views of CaBPMGLY·H2O and PbBPMGLY·H2O are shown in Figures 5 and 6, respectively.

Figure 4. Effect of pH on crystal size and morphology of Ca-BPMGLY crystals.

magnifications. The same crystalline compound is obtained in all studied pH values, as evidenced by XRD and FT-IR studies. Also, the same needle-like morphology is observed. However, the size of the needle crystallites is profoundly affected. At the lowest pH value 2.3 needles have an average length of ∼500 μm and width of ∼3−5 μm. Increase of synthesis pH causes substantial reduction in needle width but no observable change in needle length. For example, at pH values of 3.1 and 3.9 the needle width is ∼500 nm. Further pH increase to 4.7 causes an increase in needle width to ∼3 μm, but only in some crystals. Finally, at the pH 5.7 the proportion of wider needles further increases with a crystal width of ∼8 μm. These observations reveal that a wide range of synthesis pH values must be evaluated in order to obtain the optimum size crystals for single crystal X-ray crystallography. Description of the Crystal Structures. CaBPMGLY·H2O, SrBPMGLY·H2O, and PbBPMGLY·H2O have very similar 3D

Figure 5. Crystal structure of CaBPMGLY·H2O (top, 50% probability ellipsoids), Ca coordination environment (middle), and crystal packing along the b axis (bottom). 5238



Article

molecule bridges Ba1 and Ba2. The four crystallographically independent Ba-atoms (Ba4 is located on an inversion center) are 8-, 9-, 8-, and 6-coordinate, respectively (Table 2). Topological analysis. To better understand the intricate structures of the above 2D or 3D metal−organic networks formed by BPMGLY, we have carried out their topological analysis.23 A concept of the simplified underlying net24,25 has been applied, which implies several structure simplification procedures, namely the contraction of the bridging moieties to their centroids and elimination of all terminal ligands. For comparative purposes, the previously reported Mg-BPMGLY 2D coordination polymer18 has also been analyzed and discussed below along with the topological description of the novel Ca, Sr, Ba, and Pb containing derivatives. Mg-BPMGLY. An underlying 2D network of Mg-BPMGLY has been generated by reducing the μ3-BPMGLY moieties to their centroids and removing the terminal H2O ligands. The obtained network can be described as an underlying net (Figure 8) constructed from the topologically equivalent 3-connected Mg1 and μ3-BPMGLY nodes. This net can be topologically classified as a uninodal 3-connected network with the hcb [Shubnikov hexagonal plane net/(6,3)] topology and the corresponding point symbol of (63).23,26 Although the present type of topology is rather common,23 only a limited number of magnesium containing hcb networks have been identified.27 Ca-BPMGLY. In contrast to Mg-BPMGLY, the structure of Ca-BPMGLY features a 3D metal−organic framework which, after the simplification procedure (μ5-BPMGLY blocks reduced to their centroids and terminal H2O ligands omitted), gives rise to an underlying net assembled from the topologically equivalent 5-connected Ca1 and μ5-BPMGLY nodes (Figure 9). This network is topologically classified as a uninodal 5-connectted net with the bnn [hexagonal boron nitride] topology and the point symbol of (46.64). Although a considerable number of compounds with the bnn topology have been reported,23,26 Ca-BPMGLY represents the first alkaline earth metal containing network with such a topology. Sr-BPMGLY. The structure of Sr-BPMGLY also reveals a 3D metal−organic framework formed by the μ5-BPMGLY blocks. After omitting terminal H2O ligands and contracting the μ5-BPMGLY moieties to their centroids, a simplified underlying net has been generated (Figure 10). Although this net is also assembled from the topologically equivalent 5-connected metal (Sr1) and μ5-BPMGLY nodes, it is topologically different from that of Ca-BPMGLY. In fact, the topological analysis of Sr-BPMGLY reveals a uninodal 5-connected network with the vbj topology described by the point symbol of (45.65).23 Despite the fact that this topological type has been predicted, to our knowledge,23,28 no examples of compounds with the vbj network have been reported. Ba-BPMGLY. In contrast to Mg-BPMGLY, Ca-BPMGLY, and Sr-BPMGLY, the 2D double-layered network of BaBPMGLY is significantly more complex due to the presence of four types of barium atoms (Ba1, Ba2, Ba3, Ba4), two distinct μ7- and μ8-BPMGLY building blocks, and μ2-H2O (O17) linkers. After running a simplification procedure,23,25 we have obtained an underlying 2D net (Figure 11) that is built from the 4-connected Ba1/Ba3 and 6-connected Ba2/Ba4 nodes (all are topologically distinct), 7-connected μ7-BPMGLY (with P1/P2 atoms) and 8-connected μ8-BPMGLY (with P3/P4 atoms), as well as 2-connected μ2-H2O linkers.

Figure 6. Crystal structure of PbBPMGLY·H2O (top, 50% probability ellipsoids), Pb coordination environment (middle), and crystal packing along the b axis (middle).

In contrast to the Ca, Sr, and Pb analogs, Ba3.5(BPMGLY)2· 6H2O has a different and more complex 2D layered structure (Figure 7). One of the two crystallographically unique BPMGLY ligands carries a 4− charge, while the second one carries a 3− charge. In both cases, the carboxylic acid group is deprotonated (−COO−) and the N atom is protonated (−NH+). Both phosphonic acid groups are doubly deprotonated (−PO32−) in the 4− ligand, while in the 3− ligand one phosphonic acid group is singly deprotonated (−PO3H−) and the other is doubly deprotonated (−PO32−). All ligand O atoms are coordinated to Ba except one carboxylate and one phosphonate O atom from the 4− ligand, and the protonated phosphonate O atom from the 3− ligand, which point toward the interlayer region and are involved in hydrogen bonding with four independent water molecules (of which two are disordered). A fifth H2O molecule is coordinated to Ba1, and a sixth H2O 5239



Article

Figure 7. Crystal structure of Ba3.5(BPMGLY)2·6H2O (top left, 50% probability ellipsoids), Ba coordination environment (top middle), and crystal packing along the a axis (bottom) and perpendicular to the 001 plane (top right).

Figure 9. Topological representation (view along the a axis) of the underlying uninodal 5-connected 3D net in Ca-BPMGLY with the bnn topology and the point symbol of (46.64). Color codes: 5-connected Ca1 nodes (green) and centroids of 5-connected μ5-BPMGLY nodes (yellow).

Figure 8. Topological representation (view along the c axis) of the underlying uninodal 3-connected corrugated 2D net in Mg-BPMGLY with the hcb [Shubnikov hexagonal plane net/(6,3)] topology and the point symbol of (63). Color codes: 3-connected Mg1 nodes (green) and centroids of 3-connected μ3-BPMGLY nodes (yellow).

wherein the (3.416.5.63), (3.418.52.67), (32.43.5), (32.49.53.6), (410.52.63), and (46) indices belong to the μ7-BPMGLY, μ8-BPMGLY, Ba1, Ba2, Ba4, and Ba3 nodes, respectively. The novelty of the present type of topology has been confirmed by a search of different databases.23,26,28

The topological analysis23 of this network reveals a very complex hexanodal 4,4,6,6,7,8-connected net with an undocumented topology defined by the point symbol of (3.416.5.63)2(3.418.52.67)2(32.43.5)2(32.49.53.6)2(410.52.63)(46)2, 5240



Article

a neutral binuclear [(H2O)2Co(BPMGLY)Co(NH3)2(H2O)3]0 species. By lowering the synthesis pH even further to 1.5, the same group isolated and structurally characterized the mononuclear complex [Co(BPMGLY)(H2O)2]·2H2O.31 The intriguing feature of this compound is that it contains a Co-bound N atom from BPMGLY, and a protonated, Co-bound −COOH moiety. Mao et al. have hydrothermally synthesized (at 180 °C for 5 days, no pH was reported) and structurally characterized the 3D coordination polymer [Zn2(BPMGLY)].32 Both Zn atoms are tetrahedrally coordinated by three phosphonate oxygen atoms and one carboxylate oxygen atom from four different ligands. The ZnO4 tetrahedra are further interconnected by bridging phosphonate and carboxylate groups, resulting in the formation of a 3D network. Ma et al. reported the hydrothermal synthesis and structural characterization of the compounds [NH3(CH2)3NH3](NH4)4[Ni(BPMGLY)(H 2 O)] 2 , (H 3 O) 3 [Ni(BPMGLY)(H 2 O) 2 ]· 4H2O, and (H3O)[Co(BPMGLY)(H2O)2]·2H2O.33 The first compound contains discrete dinuclear anionic Ni2 units, charge balanced by propyldiammonium and ammonium cations. The second contains discrete mononuclear Ni anionic units charge balanced by hydronium cations. The core of the third compound is an anionic Co center (similar to that with Ni), balanced by a hydronium cation. Lastly, two zirconium compounds were synthesized (under mild heating at 80 °C and pH ∼2.1) and characterized by powder X-ray diffraction. They are Zr 3H8(BPMGLY)4· 2H2O and Zr(BPMGLY)2·2H2O.34 The first has a layered structure based on the connection of two different kinds of monodimensional chains of ZrO6 octahedra and PO3C tetrahedra, both running along the a axis and connected via phosphonate tetrahedra along the c axis. The second has a 3D structure based on monodimensional inorganic chains composed of ZrO6 octahedra and PO3C tetrahedra, running along the a axis and connected by the BPMGLY moieties in the other dimensions.

Figure 10. Topological representation (view along the b axis) of the underlying uninodal 5-connected 3D net in Sr-BPMGLY with the vbj topology and the point symbol of (45.65). Color codes: 5-connected Sr1 nodes (green) and centroids of 5-connected μ5-BPMGLY nodes (yellow).

■

Figure 11. Topological representation (view along the c axis) of the underlying 2D double-layer in Ba-BPMGLY featuring a very complex hexanodal 4,4,6,6,7,8-connected net with a unique topology. Color codes: 4- and 6-connected Ba1−Ba4 nodes (green), centroids of 7- and 8-connected BPMGLY nodes (yellow), centroids of 2-connected μ2-H2O linkers (red).

CONCLUSIONS This work is part of our continuing efforts to map metal phosphonate chemistry from a synthetic and structural point of view.11,14,18,21,35 Herein, we reported a family of four hybrid metal phosphonate compounds that include divalent metal ions (Ca, Sr, Ba, and Pb) and the tripodal, glycine-derived ligand BPMGLY. These compounds were obtained by hydrothermal reactions in acidic aqueous solutions (pH range 2.3−5.7). Structural analysis revealed that Ca-BPMGLY, Sr-BPMGLY, and Pb-BPMGLY have very similar 3D coordination polymer structures, with the latter two being isostructural. However, Ba-BPMGLY has a different and very intricate 2D layered structure. From a topological point of view, we have also shown that BPMGLY is a useful building block for the generation of a series of 2D (Mg, Ba) or 3D (Ca, Sr) alkaline earth metal−organic networks that feature diverse topologies, the complexity of which increases periodically following the Mg < Ca ≤ Sr ≪ Ba trend. In particular, a uninodal 3-connected hcb net has been identified in Mg-BPMGLY, whereas Ca-BPMGLY and Sr-BPMGLY reveal uninodal 5-connected nets with the bnn and vbj topology, respectively. A significantly more complex hexanodal 4,4,6,6,7,8-connected net with a novel topology has been determined in Ba-BPMGLY. Apart from Sr-BPMGLY, the vbj topology has also been found in the Pb-BPMGLY

Pb-BPMGLY. From a topological viewpoint, the 3D metal− organic framework of Pb-BPMGLY is assembled from the 5-connected Pb1 and μ5-BPMGLY nodes that are topologically equivalent. This uninodal 5-connected net features the vbj topology,23 which is identical to that identified in Sr-BPMGLY, therefore it is not discussed in detail. Concise Overview of Other Reported Metal-BPMGLY Structures. An anionic cobalt-BPMGLY compound [(NH4)3[Co(BPMGLY)(H2O)2]·4H2O] prepared at pH 8 was recently reported.29 Its X-ray crystal structure reveals the presence of discrete [Co(BPMGLY)(H2O)2]3− anions and NH4+ counterions. The N atom of BPMGLY is not protonated, and it is found coordinated to the Co center. There is extensive hydrogen bonding in the structure that results in the formation of 1D chains. The same authors solved the crystal structure of (NH4) 4[Co(H 2O) 6][(H 2O) 2Co(BPMGLY)Co(NH3)2(H2O)3]2[Co(BPMGLY)(H2O)2]2·10H2O· 1.36CH3CH2OH which was prepared at much lower pH 5.5.30 The structure is composed from a mononuclear [Co(H2O)6]2+ core unit, a mononuclear [Co(BPMGLY)(H2O)2]3− species, and 5241



Article

derivative. These compounds represent the first examples of vbj networks, while Ca-BPMGLY affords the first alkaline earth metal containing network with the bnn topology. The study thus also contributes to the topological identification and classification of novel topological motifs in metal−organic networks determined by the versatile carboxyphosphonate building blocks.

■

Ahlgren, M. J.; Järvinen, T.; Vepsäläinen, J. J. Synthesis 2001, 4, 633− 637. (6) (a) Villemin, D.; Moreau, B.; Kaid, M.; Didi, M. A. Phosphorus Sulfur Silicon 2010, 185, 1538−1586. (b) Bowen, T.; Planalp, R. P.; Brechbiel, M. W. Bioorg. Med. Chem. Lett. 1996, 6, 807−810. (c) Didi, M. A.; Elias, A.; Villemin, D. Solv. Extr. Ion Exch. 2002, 20, 505−513. (d) Zon, J.; Kong, D.; Gagnon, K.; Perry, H.; Holliness, L.; Clearfield, A. Dalton Trans. 2010, 39, 11008−11018. (e) Cigala, R. M.; Cordaro, M.; Crea, F.; De Stefano, C.; Fracassetti, V.; Marchesi, M.; Milea, D.; Sammartano, S. Ind. Eng. Chem. Res. 2014, 53, 9544−9553. (7) (a) Garczarek, P.; Janczak, J.; Zon, J. J. Mol. Struct. 2013, 1036, 505−509. (b) Hirao, T.; Masunaga, T.; Ohshiro, Y.; Agawa, T. Synthesis 1981, 56−57. (c) Tang, S.-F.; Pan, X.-B.; Lv, X.-X.; Zhao, X.B. J. Solid State Chem. 2013, 197, 139−146. (8) (a) Montoneri, E. Phosphorus Sulfur Silicon Relat. Elem. 1991, 55, 201−204. (b) Montoneri, E.; Gallazzi, M. C. Dalton Trans. 1989, 1819−1823. (c) Du, Z.-Y.; Zhao, C.-C.; Zhou, Z.-G.; Wang, K.-J. J. Mol. Struct. 2013, 1035, 183−189. (d) Serre, C.; Stock, N.; Bein, T.; Férey, G. Inorg. Chem. 2004, 43, 3159−3163. (e) Adani, F.; Casciola, M.; Jones, D. J.; Massinelli, L.; Montoneri, E.; Roziere, J.; Vivani, R. J. Mater. Chem. 1998, 8, 961−964. (9) (a) Delain-Bioton, L.; Lohier, J. F.; Villemin, D.; Sopková-de Oliveira Santos, J.; Hix, G. B.; Jaffrès, P. A. Acta Cryst. C 2008, 64, o47−o49. (b) Latham, K.; Coyle, A. M.; Rix, C. J.; Fowless, A.; White, J. M. Polyhedron 2007, 26, 222−236. (c) Wu, J.; Sun, W.; Sun, X.; Xia, H.-G. Green Chem. 2006, 8, 365−367. (d) Jones, K. M. E.; Mahmoudkhani, A. H.; Chandler, B. D.; Shimizu, G. K. H. CrystEngComm 2006, 8, 303−305. (10) (a) Maxim, C.; Matni, A.; Geoffroy, M.; Andruh, M.; Hearns, N. G. R.; Clerac, R.; Avarvari, N. New J. Chem. 2010, 34, 2319−2327. (b) Maltezou, E.; Stylianou, M.; Roy, S.; Drouza, C.; Keramidas, A. D. Bioinorg. Chem. Appl. 2010, No. 563875. (c) Aliouane, N.; Hélesbeux, J.-J.; Douadi, T.; Khan, M. A.; Bouet, G.; Chafaa, S.; Duval, O. Phosphorus Sulfur Silicon 2011, 186, 354−364. (d) Du, Z.-Y.; Wen, H.R.; Xie, Y.-R. J. Mol. Struct. 2008, 891, 272−277. (11) Demadis, K. D.; Katarachia, S. D.; Raptis, R. G.; Zhao, H.; Baran, P. Cryst. Growth Des. 2006, 6, 836−838. (12) Taddei, M.; Costantino, F.; Ienco, A.; Comotti, A.; Dau, P. V.; Cohen, S. M. Chem. Commun. 2013, 49, 1315−1317. (13) (a) Wharmby, M. T.; Mowat, J. P. S.; Thompson, S. P.; Wright, P. A. J. Am. Chem. Soc. 2011, 133, 1266−1269. (b) Groves, J. A.; Miller, S. R.; Warrender, S. J.; Mellot-Draznieks, M.; Lightfoot, P.; Wright, P. A. Chem. Commun. 2006, 3305−3307. (c) Miller, S. R.; Pearce, G. M.; Wright, P. A.; Bonino, F.; Chavan, S.; Bordiga, S.; Margiolaki, I.; Guillou, N.; Ferey, G.; Bourrelly, S.; Llewellyn, P. L. J. Am. Chem. Soc. 2008, 130, 15967−15981. (d) Wharmby, M. T.; Pearce, G. M.; Mowat, J. P. S.; Griffin, J. M.; Ashbrook, S. E.; Wright, P. A.; Schilling, L.-H.; Lieb, A.; Stock, N.; Chavan, S.; Bordiga, S.; Garcia, E.; Pirngruber, G. D.; Vreeke, M.; Gora, L. Microporous Mesoporous Mater. 2012, 157, 3−17. (14) Demadis, K. D.; Stavgianoudaki, N.; Grossmann, G.; Gruner, M.; Schwartz, J. L. Inorg. Chem. 2009, 48, 4154−4164. (15) Zon, J.; Garczarek, P.; Bialek, M. In Metal Phosphonate Chemistry: From Synthesis to Applications; Clearfield, A., Demadis, K. D., Eds; Royal Society of Chemistry: London, 2012; pp 170−191. (16) Tusek-Bozic, Lj. Curr. Med. Chem. 2013, 20, 2096−2117. (17) Mao, J.-G.; Wang, Z.; Clearfield, A. New J. Chem. 2002, 26, 1010−1014. (18) Demadis, K. D.; Famelis, N.; Cabeza, A.; Aranda, M. A. G.; Colodrero, R. M. P.; Infantes-Molina, A. Inorg. Chem. 2012, 51, 7889− 7896. (19) APEX2, version 2013.4-1; Bruker AXS Inc.: Madison, WI, 2013. (20) Shkol’nikova, L. M.; Porai-Koshits, M. A.; Dyatlova, N. M.; Yaroshenko, G. F.; Rudomino, M. V.; Kolova, E. K. J. Struct. Chem. 1982, 23, 737−746. (21) Demadis, K. D.; Papadaki, M.; Raptis, R. G.; Zhao, H. Chem. Mater. 2008, 20, 4835−4846. (22) Long, L.-S. CrystEngComm 2010, 12, 1354−1365.

ASSOCIATED CONTENT

* Supporting Information S

FT-IR spectra, various views of the crystal structures not included in the paper, calculated and measured XRD patterns, and cif files for Ca-BPMGLY (CaBPMGLY·H2O), Sr-BPMGLY (SrBPMGLY·H2O), Ba-BPMGLY (Ba3.5(BPMGLY)2·6H2O), and Pb-BPMGLY (PbBPMGLY·H2O). This material is available free of charge via the Internet at http://pubs.acs.org.

■

AUTHOR INFORMATION

Corresponding Authors

*E-mail: [email protected]. *E-mail: [email protected]. Author Contributions

The manuscript was written through contributions of all authors. All authors have given approval to the final version of the manuscript. Funding

A.M.K. acknowledges the Foundation for Science and Technology (FCT), Portugal (PTDC/QUI-QUI/121526/2010, PEst-OE/QUI/UI0100/2013). Notes

The authors declare no competing financial interest.

■

REFERENCES

(1) Metal Phosphonate Chemistry: From Synthesis to Applications; Clearfield, A., Demadis, K. D., Eds.; The Royal Society of Chemistry: London, 2012. (2) (a) Gagnon, K. J.; Perry, H. P.; Clearfield, A. Chem. Rev. 2012, 112, 1034−1054. (b) Clearfield, A. Dalton Trans. 2008, 44, 6089− 6102. (c) Maeda, K. Microporous Mesoporous Mater. 2004, 73, 47−55. (d) Fromm, K. M. Coord. Chem. Rev. 2008, 252, 856−885. (e) Ma, T.Y.; Yuan, Z.-Y. ChemSusChem 2011, 4, 1407−1419. (f) Mitra, M.; Ghosh, R. Inorg. Chem. Commun. 2012, 24, 95−103. (g) Zhu, Y.-P.; Ma, T.-Y.; Liu, Y.-L.; Ren, T.-Z.; Yuan, Z.-Y. Inorg. Chem. Front. 2014, 1, 360−383. (h) Vivani, R.; Alberti, G.; Costantino, F.; Nocchetti, M. Microporous Mesoporous Mater. 2008, 107, 58−70. (i) Guerrero, G.; G. Alauzun, J. G.; Granier, M.; Laurencin, D.; Mutin, P. H. Dalton Trans. 2013, 42, 12569−12585. (j) Papadaki, M.; Demadis, K. D. Comments Inorg. Chem. 2009, 30, 89−118. (k) Queffélec, C.; Petit, M.; Janvier, P.; Knight, D. A.; Bujoli, B. Chem. Rev. 2012, 112, 3777−3807. (3) Alberti, G.; Costantino, U.; Allulli, S.; Tomassini, N. J. Inorg. Nucl. Chem. 1978, 40, 1113−1117. (4) Poojary, M. D.; Hu, H.-L.; Campbell, F. L., III; Clearfield, A. Acta Crystallogr. 1993, B49, 996−1001. (5) (a) Alanne, A.-L.; Hyvönen, H.; Lahtinen, M.; Ylisirniö, M.; Turhanen, P.; Kolehmainen, E.; Peräniemi, S.; Vepsäläinen, J. Molecules 2012, 17, 10928−10945. (b) Failla, S.; Consiglio, G.; Finocchiaro, P. Phosphorus Sulfur Silicon 2011, 186, 983−988. (c) Even, P.; Guenin, E.; Benramdame, M.; Quidu, P.; El Manouni, D.; Lecouvey, M. Lett. Org. Chem. 2004, 1, 75−77. (d) Aliouane, N.; Chafaa, S.; Douadi, T.; Helesbeux, J.-J.; Khan, M. A.; Duval, O.; Bouet, G. Heteroat. Chem. 2010, 21, 51−62. (e) Rueff, J.-M.; Barrier, N.; Boudin, S.; Dorcet, V.; Caignaert, V.; Boullay, P.; Hix, G. B.; Jaffres, P.A. Dalton Trans. 2009, 10614−10620. (f) Bhattacharya, A. K.; Thyagarajan, G. Chem. Rev. 1981, 81, 415−430. (g) Turhanen, P.; Vepsäläinen, J. Beilstein J. Org. Chem. 2006, 2, 2. (h) Turhanen, P. A.; 5242



Article

(23) (a) Blatov, V. A. IUCr CompComm Newsl. 2006, 7, 4−38. (b) Blatov, V. A.; Shevchenko, A. P.; Proserpio, D. M. Cryst. Growth Des. 2014, 14, 3576−3586. (24) (a) Blatov, V. A.; Proserpio, D. M. In Modern Methods of Crystal Structure Prediction; Oganov, A. R., Ed.; Wiley: Weinheim, Germany, 2010; pp 1−28. (b) Blatov, V. A.; O’Keeffe, M.; Proserpio, D. M. CrystEngComm 2010, 12, 44−48. (c) Alexandrov, E. V.; Blatov, V. A.; Kochetkova, A. V.; Proserpio, D. M. CrystEngComm 2011, 13, 3947− 3958. (25) O’Keeffe, M.; Yaghi, O. M. Chem. Rev. 2012, 112, 675−702. (26) For the Reticular Chemistry Structure Resource (RCSR) Database, see: O’Keeffe, M.; Peskov, M. A.; Ramsden, S. J.; Yaghi, O. M. Acc. Chem. Res. 2008, 30, 1782−1789. (27) For selected examples of Mg networks with the hcb topology, see: (a) Platero-Prats, A. E.; de la Pena-O’Shea, V. A.; Proserpio, D. M.; Snejko, N.; Gutierrez-Puebla, E.; Monge, A. J. Am. Chem. Soc. 2012, 134, 4762−4771. (b) Banerjee, D.; Finkelstein, J.; Smirnov, A.; Forster, P. M.; Borkowski, L. A.; Teat, S. J.; Parise, J. B. Cryst. Growth Des. 2011, 11, 2572−2579. (c) Zhang, J.; Bu, J. T.; Chen, S.; Wu, T.; Zheng, S.; Chen, Y.; Nieto, R. A.; Feng, P.; Bu, X. Angew. Chem., Int. Ed. 2010, 49, 8876−8879. (28) See the Cambridge Structural Database (CSD, version 5.35, 2014): Allen, F. H. Acta Crystallogr. 2002, B58, 380. (29) Menelaou, M.; Daskalakis, M.; Mateescu, A.; Raptopoulou, C. P.; Terzis, A.; Mateescu, C.; Tangoulis, V.; Jakusch, T.; Kiss, T.; Salifoglou, A. Polyhedron 2011, 30, 427−437. (30) Mateescu, A.; Gabriel, C.; Raptis, R. G.; Baran, P.; Salifoglou, A. Inorg. Chim. Acta 2007, 360, 638−648. (31) Mateescu, A.; Raptopoulou, C. P.; Terzis, A.; Tangoulis, V.; Salifoglou, A. Eur. J. Inorg. Chem. 2006, 1945−1956. (32) Mao, J.-G.; Zhike Wang, Z.; Clearfield, A. New J. Chem. 2002, 26, 1010−1014. (33) Ma, K.; Xu, J.; Zhang, L.; Shi, J.; Zhang, D.; Zhu, Y.; Fan, Y.; Song, T. New J. Chem. 2009, 33, 886−892. (34) Taddei, M.; Donnadio, A.; Costantino, F.; Vivani, R.; Casciola, M. Inorg. Chem. 2013, 52, 12131−12139. (35) (a) Bazaga-García, M.; Colodrero, R. M. P.; Papadaki, M.; Garczarek, P.; Zoń, J.; Olivera-Pastor, P.; Losilla, E. R.; León-Reina, L.; Aranda, M. A. G.; Choquesillo-Lazarte, D.; Demadis, K. D.; Cabeza, A. J. Am. Chem. Soc. 2014, 136, 5731−5739. (b) Demadis, K. D.; Panera, A.; Anagnostou, Z.; Varouhas, D.; Kirillov, A. M.; Cisarova, I. Cryst. Growth Des. 2013, 13, 4480−4489. (c) Colodrero, R. M. P.; Angeli, G. K.; Bazaga-Garcia, M.; Olivera-Pastor, P.; Villemin, D.; Losilla, E. R.; Martos, E. Q.; Hix, G. B.; Aranda, M. A. G.; Demadis, K. D.; Cabeza, A. Inorg. Chem. 2013, 52, 8770−8783. (d) Colodrero, R. M. P.; Cabeza, A.; Olivera-Pastor, P.; Losilla, E. R.; Papathanasiou, K. E.; Stavgianoudaki, N.; Sanz, J.; Sobrados, I.; Choquesillo-Lazarte, D.; García-Ruiz, J. M.; León Reina, L.; Aranda, M. A. G.; Corvillo, P. A.; Demadis, K. D. Chem. Mater. 2012, 24, 3780−3792. (e) Stavgianoudaki, N.; Papathanasiou, K. E.; Colodrero, R. M. P.; ChoquesilloLazarte, D.; Garcia-Ruiz, J. M.; Cabeza, A.; Aranda, M. A. G.; Demadis, K. D. CrystEngComm 2012, 14, 5385−5389. (f) Colodrero, R. M. P.; Olivera-Pastor, P.; Losilla, E. R.; Alonso, D. H.; Aranda, M. A. G.; Leon-Reina, L.; Rius, J.; Demadis, K. D.; Moreau, B.; Villemin, D.; Rey, F.; Cabeza, A. Inorg. Chem. 2012, 51, 7689−7698. (g) Colodrero, R. M. P.; Olivera-Pastor, P.; Losilla, E. R.; Aranda, M. A. G.; Papadaki, M.; McKinlay, A.; Morris, R. E.; Demadis, K. D.; Cabeza, A. Dalton Trans. 2012, 41, 4045−4051. (h) Colodrero, R. M. P.; Cabeza, A.; Olivera-Pastor, P.; Choquesillo-Lazarte, D.; Garcia-Ruiz, J. M.; Turner, A.; Ilia, G.; Maranescu, B.; Papathanasiou, K. E.; Demadis, K. D.; Hix, G. B.; Aranda, M. A. G. Inorg. Chem. 2011, 50, 11202−11211. (i) Colodrero, R. M. P.; Cabeza, A.; Olivera-Pastor, P.; Rius, J.; Choquesillo-Lazarte, D.; García-Ruiz, J. M.; Papadaki, M.; Demadis, K. D.; Aranda, M. A. G. Cryst. Growth Des. 2011, 11, 1713−1722.

5243


Structural Systematics and Topological Analysis of Coordination

Recommend Documents