The IR spectrum of the nano structures

The IR spectrum of the nano-structures produced by the sonochemical method and of the bulk material produced by the solvothermal method were compared with each other in Fig. 2. The structure of Afatinib Supplier 1 was characterized by single-crystal X-ray diffraction techniques [50]. The molecular structure of the fundamental building unit for 1 is shown in Fig. 3. The asymmetric unit consists of four Zn(II) atoms, four BDC2− ligands, four bpta linkers, five DMF, and three water guest molecules. The framework is constructed from a six-connected dinuclear Zn2N4O6 node, which is octahedrally bound to four BDC ligands and two double-bpta-deckered pillars. Each BDC2− ligand acts as a μ3-bridge to link three Zn(II) atoms, in which one carboxylate group exhibits a μ2-η1:η1-bridging coordination mode, while the other adopts a monodentate structure (Fig. 3).
Fig. 4 shows the simulated XRD pattern from single crystal X-ray data of compound 1 in comparison with the XRD pattern of the as synthesized nano-structure of compound 1 by the sonochemical process. Acceptable matches were observed between the simulated and experimental XRD patterns. This indicates that the compound obtained by the sonochemical process as nano-structures is identical to that obtained by single crystal diffraction. The significant broadening of the peaks indicates that the particles are of nanometer dimensions.
The morphology and size of compound 1 prepared by the sonochemical method was characterized by scanning electron microscopy (SEM). Fig. 5 shows the SEM of the compound 1 prepared by ultrasonic generator 12W in concentration of initial reagents [Zn2+]=[BDC]=[bpta]=0.04molL−1. Also different concentrations of zinc(II), 1,4-benzenedicarboxylate and N,N′-bis(4-pyridinyl)-1,4-benzenedicarboxamide solution (0.01 and 0.006molL−1) were tested (Figs. 6 and 7). In order to investigate the role of concentration of initial reagents on the nature of products, reactions were performed with three different concentrations of initial reagents. Comparison between the samples with different concentrations shows that high concentrations of initial reagents decreased particles size. Thus, particles sizes produced using lower concentrations of initial reagents (0.006molL−1, Fig. 7) are bigger than particles size produced using higher concentrations (0.04 and 0.01molL−1, Figs. 5 and 6, respectively). More interestingly that, as shown in Fig. 7, decreasing of concentration of initial reagents ultimate to prepared rod-like nano-structure compound 1 (Fig. 7). The morphologies and size of nano-structure of the as-prepared samples for different reaction times were characterized by SEM. Fig. 8 shows the SEM image of compound 1 with reaction time of 30min (Zn(II)=BDC=bpta=0.006molL−1, 12W). The results show that the size of the nanoparticles increased with increasing reaction times. Thus, smaller particles (for 15min, see Fig. 7) were achieved by sonocrystallization at shorter times when compared with 30min (Fig. 8). To investigate the role of power ultrasound irradiation on the nature of products, reactions were performed under diverse power ultrasound irradiation too (Zn(II)=BDC=bpta=0.006molL−1, 12 and 24W). Comparison between the samples with different powers ultrasound irradiation shows that increasing of power from 12 to 24W leads to decreasing of sizes of the nanoparticles (Fig. 9). Table 1 gives an overview of the comparison of the concentration of initial reagents, times effect and different powers of ultrasonic irradiation on the morphologies and sizes of nano-structure of the compound 1.
Thermogravimetric analysis of 1 showed that guest molecules are eliminated from the network (calcd 16.1%; found 16.5%, which correspond to loss of 20 DMF molecules and 12 H2O molecules per unit cell) when the temperature is increased from room temperature to about 270°C [50].

Nanoparticles and nanorods of porous metal–organic framework, [Zn4(BDC)4(bpta)4]·5DMF·3H2O (1), (bpta=N,N′-bis(4-pyridinyl)-1,4-benzenedicarboxamide, BDC=1,4-dicarboxylate, DMF=N,N-dimethylformamide) have been synthesized under ultrasound irradiation. Structural information of the nanoparticles was compared with the structural information of crystals of compound 1. Morphology and sizes of the nano-structures were investigated in different concentrations of initial reagents, different powers of ultrasonic irradiation and various reaction times. Results show an increase in the particles size as the concentrations of initial reagents is decreased. It is an interesting point that low concentration of initial reagents leaded to rod-like nano-structures morphology. Also the shorter reaction times and using of different powers of ultrasonic irradiation lead to decreasing the size of nano-structures.