Characterization of an Oxalate-Phosphate-Amine Metal Organic Framework (OPA-MOF) Exhibiting

Characterization of an oxalate-phosphate-amine metal organic framework (OPA-MOF) exhibiting properties suited for innovative applications in agriculture

Manuela Anstoetz*1, Neeraj Sharma2,Malcolm Clark1,3, and Lachlan H. Yee1,3

1 School of Environment, Science and Engineering, Southern Cross University, Lismore NSW 2480, Australia

2 School of Chemistry, UNSW Australia, Sydney NSW 2052, Australia

3 Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore NSW 2480, Australia

* Corresponding author, email:

Morphology and Topography

The predominant morphology of both compounds is to form large macroscopic aggregates of platy to tabular crystallites; the aggregates display a white/clear or pink colour (Fig. 1 a, b); the colours might indicate a multiphasic precipitate. Individual crystallites (observed under the optical microscope) in OPA-MOF (I) range from 200x200x20 to 80x80x10 µm for platy crystallites, and 200x400x20 to 80x200x10 µm for tabular crystallites (Fig. 1 c), while crystallites in OPA-MOF (II) are generally small plates, with sizes around 50x50x5 µm (Fig. 1 d). The aggregates form different habits, however, with compound (I) forming both sphere-like (“Bucky-balls”), and massive aggregates where crystallites are arranged as radial bundles (Fig. 1 a). Compound (II) forms predominantly massive aggregates from fine platy crystallites (Fig. 1 d).

SI-Fig. 1 - Stereo micrographs of OPA-MOF compounds (I, a,c) and (II b, d)aggregates (a, b) of OPA-MOFs forming white or pink coloured masses (a, b); individual platy crystallites of 200 µm lengths for OPA-MOF (I; c) and very fine platy crystallites of 50 µm lengths for OPA-MOF (II; d); scale bars are 1mm (a), 5 mm (b), and 200 µm (c, d).

Heat induced decomposition of OPA-MOF compounds (I) and (II)

SI-Fig. 2 Synchrotron PXRD patterns of OPA-MOF compounds (I) and (II) for heat decomposition at 550 K (I) and 600 K (II)showing the complete decomposition of the compound (I) at 550 K, and the temperature stable phase remaining in compound (II) at 600 K; peaks at 8.19 and 5.89 Å appear to correspond to the secondary phase identified in the compound, while the peak at 6.93Å appears to be related to the secondary phase in this compound.

Crystal structure and refinement details

SI-Table 1 A - Crystal structure and refinement details

Compound (I) / Compound (II)
Composition / C8Fe8N16O52P8 / C8Fe8N16O52P8
Crystal system and space group / Orthorhombic Pccm / Orthorhombic Pccm
Temperature (K) / 173(2) / 173(2)
a, b, c (Å) / 10.150(2), 11.770(2), 12.510(3) / 10.170(2), 11.886(2) 12.533(3)
Z / 1 / 1
V (Å3) / 1494.5(5) / 1515.0(5)
Data collection
Radiation type / Synchrotron, 0.71023 / Synchrotron, 0.71023
Crystal colour/shape / Transparent prism / Transparent prism
hklrange / -13 < h < 13
-15 < k < 15
-16 < l < 16 / -12 < h < 12
-15 < k < 15
-16 < l < 16
 range / 2.65 <  < 27.92 / 2.64 <  < 27.92
No. of measured reflections / 1882 / 1834
No. of reflections with I > 2(I) / 1769 / 1650
Refinement
No. of parameters / 120 / 109
Rall / 4.86 % / 7.72%
2 / 1.103 / 1.101

SI-Table 1 B - Crystal and Refinement details

Crystal structure / Compound (I) / Compound (II)
Fe(1) position / x = 0.05953(7), y = 0.27325(6), z = 0 / x = 0.05610(7), y = 0.27263(6), z = 0
Fe(1) isotropic ADP / 0.0100(2) / 0.0235(3)
Fe(2) position / x = 0.22791(7), y = 0, z = 0.25 / x = 0.22712(11), y = 0, z = 0.25
Fe(2) isotropic ADP / 0.0090(2) / 0.0235(3)
P(1) position / x = 0, y = 0.20132(11), z = 0.25 / x = 0, y = 0.20015(15), z = 0.25
P(1) isotropic ADP / 0.0091(3) / 0.0220(4)
P(2) position / x = 0.28617(12), y = 0.08772(11), z = 0 / x = -0.28233(19), y = -0.08809(15), z = 0
P(2) isotropic ADP / 0.0097(3) / 0.0222(4)
O(1) position / x = 0.0432(3), y = 0.2776(2), z = 0.1574(2) / x = 0.0418(5), y = 0.2760(3), z = 0.1571(3)
O(1) isotropic ADP / 0.0171(6) / 0.0352(10)
O(2) position / x = -0.0560(4), y = 0.1343(4), 0 / x = -0.0608(8), y = 0.1370(6), 0
O(2) isotropic ADP / 0.0192(8) / 0.0446(17)
O(3) position / x = -0.1059(4), y = 0.3836(3), z = 0 / x = -0.1067(6), y = 0.3844(5), z = 0 – O5
O(3) isotropic ADP / 0.0165(8) / 0.0346(13)
O(4) position / x = 0.2342(3), y= 0.0243(3), z = 0.0970(2) / x = -0.2373(5), y= -0.0240(4), z = -0.0968(3)
O(4) isotropic ADP / 0.0195(6) / 0.0353(10) – O3
O(5) position / x = 0.2373(4), y = 0.2106(3), z = 0 / x = 0.2345(7), y = 0.2207(5), z = 0
O(5) isotropic ADP / 0.0194(8) / 0.0401(15)
O(6) position / x = 0.1144(3), y = -0.1264(2), z = 0.2128(2) / x = -0.1147(4), y = -0.1257(4), z = -0.2145(3)
O(6) isotropic ADP / 0.0186(6) / 0.0338(9)
O(7) position / x = 0.4381(4), y = 0.0921(4), z = 0 / x = -0.4360(6), y = -0.0959(6), z = 0
O(7) isotropic ADP / 0.0193(8) / 0.0379(14)
O(8) position / x = 0.3899(3), y = -0.1132(2), z = 0.2403(2) / x = -0.3908(4), y = -0.1127(4), z = -0.2396(2)
O(8) isotropic ADP / 0.0163(6) / 0.0352(10)
O(9) position / x = 0.1507(4), y = 0.4306(3), z = 0 / x = 0.1499(6), y = 0.4300(5), z = 0
O(9) isotropic ADP / 0.0136(7) / 0.0136(7)
C(1) position / x = -0.0756(5), y = 0.4863(5), z = 0 / x = -0.0739(9), y = 0.4874(7), z = 0
C(1) isotropic ADP / 0.0146(10) / 0.0310(17)
C(2) position / x = 0.5, y = -0.0657(4), z = 0.25 / x = -0.5, y = -0.0653(7), z = -0.25
C(2) isotropic ADP / 0.0132(10) / 0.0291(16)
N(1) position / x = 0.110(2), y = 0.5, z = 0.25 / x = 0.089(2), y = 0.5, z = 0.25
N(1) isotropic ADP / 0.165(10) / 0.131(7)
N(2) position / x = 0.3313(15), y = -0.3510(9), z = 0.2979(17) / x = -0.312(2), y = 0.3440(16), z = -0.2832(17)
N(2) isotropic ADP / 0.222(10) / 0.174(7)
N(3) position / x = 0.6509(14), y = 0.2422(16), z = 0 / x = -0.620(6), y = -0.262(5), z = 0
N(3) isotropic ADP / 0.243(16) / 0.38(3)