Supplementary information
Synthesis optimization of carbon supported ZrO2 nanoparticles from different organometallic precursors
PankajMadkikara*, XiaodongWangb, ThomasMittermeiera, AlessandroH.A. Monteverde Videlac, ChristophDenka, StefaniaSpecchiac, HubertA.Gasteigera, MichelePianaa
aChair of Technical Electrochemistry, Department of Chemistry and Catalysis Research Center, Technische Universität München, D-85748 Garching, Germany
bJohnson Matthey Catalysts (Germany) GmbH, Bahnhofstr. 43 + 96257 Redwitz, Germany
cPolitecnico di Torino, Department of Applied Science and Technology, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
* / +498928913835
Structural characterization of synthesized ZrOPc
o Elemental analysis of ZrOPc
CHNanalyses was done on a Hekatech EURO EA analyzer which is based on dynamic flash combustion technique. Zr content was analyzed by photometric method on Shimadzu UV160 photometer. Elemental analysis reveals that the elements contained in the product are close to the theoretical values of ZrOPc (Table1). The deviation from the theoretical values is likely because of phthalocyanine sublimation due to its high thermal stability, causing systematic errors in its analysis and because of unreacted starting impurities which were also confirmed in the FTIR and proton NMR spectroscopy[1].
Table S1: CHN (by combustion) and Zr (by photometry) analysis on synthesized ZrOPc.
C32H16N8OZr / Theoretical calculated / Experimental foundC / 62.0 / 58.6±0.3
H / 2.6 / 2.6±0.3
N / 18.1 / 16.0±0.3
O / 2.6 / ---
Zr / 14.7 / 13.0±0.6
o UV-Vis spectroscopy
UVVis spectroscopy was performed on PerkinElmer LAMBDA 35 UV-Vis spectrophotometer. Concentrated sulphuric acid (H2SO4) (96% Ultrapur) was used as the solvent in analysis of ZrOPc. We observed strong absorption bands centered at 308 and 809nm, attributable to electronic transitions of the inner pyrrole ring in the phthalocyanine (Pc) macrocycle (Fig.S1). The band at 308nm (B or Soret band – a2u→eg) is due to the increase of electronic density at the bridging atoms of azamethine group, whereas the band at 809nm (Q band – a1u→eg) originates from the electronic charge transfer from pyrrole to benzene functional group[2]. The peak at 719nm is the splitted component of Q band[3, 4]. Peak at 445nm is possibly because of the symmetry of Pc complex[5]. The recorded spectra are in agreement with the results by Tomachynski et al.[6].
Fig.S1 UV-Vis absorption spectra of ZrOPc in concentrated H2SO4
o NMR spectroscopy
Proton (1H) NMR spectra of ZrOPc was recorded in CDCl3 solution with a Bruker AV500 (500 MHz) spectrometer. MestReNova software was used in post-run analysis of data files including background correction, solvent referencing, and phase correction. Two predominant sets of protons are detected in 1H NMR analysis. Their chemical shifts are in the region of 9.359.15ppm and 8.258.05ppm, consistently with the literature values for the Pc protons at H1,4 and H2,3, respectively (Fig.S2)[7].
Fig.S2 1H NMR spectra of ZrOPc (H1,4 and H2,3) and unreacted C6H4(CN)2 (red asterisk) in CDCl3
Proton signals at 7.8ppm and 7.7ppm (marked by red asterisk) are assignable to unreacted 1,2 dicyanobenzene (C6H4(CN)2)[8].
o FTIR spectroscopy
Fourier transform infrared (FTIR) spectroscopy was used for identification of characteristic vibrational frequencies in ZrOPc. PerkinElmer Spectrum Two FTIR spectrometer with ATR mode was used here. Sample was pressed on the ATR-crystal by a minihand press prior to measurement. The fingerprint region of the synthesized complex is shown in Fig.S3. The band appearing at 1331cm-1 can be assigned to C–C symmetric stretching of isoindole. Another band at 1286cm-1 is due to C–N asymmetric stretching vibrations in isoindole. The absorption band at 1071cm-1 originates from C–N asymmetric stretching vibration in pyrrole. The absorption band at 891 and 729cm-1 is related to C–H bending out of plane deformation. These typical absorption bands fit very well to the characteristic bands of Pc macrocycle [9]. In addition, band at 1161cm-1 fits to CN in plane stretching, 1116cm-1 corresponds to C–H bending in plane deformation, 778cm-1 is due to CN stretching vibration. Band at 631cm-1 corresponds to CC macrocycle ring deformation. Besides, Zr coordination in the Pc ring is confirmed by the absence of the very strong absorption band at 1006cm-1 originating from the N–H bending vibration in metal-free Pc compounds as reported by Seoudi et al[9].
Fig.S3 IR absorption spectra of ZrOPc (fingerprint region)
No distinct dicyanobenzene peaks were identified due to low concentration.
In this supplementary information we would like to conclude that elemental analysis, UV-Vis, 1H-NMR, and FTIR spectroscopies confirm the successful synthesis of ZrOPc.
o X-ray diffractograms of ZrOPc and Zr(acac)4 residue
ZrO2 is clearly seen in the XRDs of ZrOPc and Zr(acac)4 residue which remains after TGA in pure Ar (Fig.S4).
Fig.S4 XRDs of ZrOPc and Zr(acac)4 residue after TGA in pure Ar
References
1. Cook M and Chambrier I.: Phthalocyanine Thin Films: Deposition and Structural Studies. In: The Porphyrin Handbook: Elsevier, (2003)
2. Mack J and Stillman M.: Electronic Structures of Metal Phthalocyanine and Porphyrin Complexes from Analysis of the UV–Visible Absorption and Magnetic Circular Dichroism Spectra and Molecular Orbital Calculations. In: The Porphyrin Handbook: Elsevier, (2003)
3. Mack J and Stillman M.: Band Deconvolution Analysis of the Absorption and Magnetic Circular Dichroism Spectral Data of ZnPc(-2) Recorded at Cryogenic Temperatures. J. Phys. Chem. 99, 7935–7945 (1995)
4. Gerasymchuk Y, Chernii V, Tomachynski L, Legendziewicz J, St. Radzki.: Spectroscopic characterization of zirconium(IV) and hafniumf(IV) gallate phthalocyanines in monolithic silica gels obtained by sol–gel method. Opt. Mater 27, 1484–1494 (2005)
5. Edwards L and Gouterman M.: Porphyrins. J. Mol. Spectrosc. 33, 292–310 (1970)
6. Tomachynski L, Chernii V, Volkov S.: Synthesis of dichloro phthalocyaninato complexes of titanium, zirconium, and hafnium. Russ. J. Inorg. Chem+ 47, 208211 (2002)
7. Guilard R, Dormond A, Belkalem M, Anderson J, Liu Y, Kadish K.: First example of 1:1 actinide-phthalocyanine complexes: synthesis, electrochemical, and spectral characterization of bis(diketonato)thorium(IV) and -uranium(IV) phthalocyaninates. Inorg. Chem. 26, 1410–1414 (1987)
8. Laulhé S, Gori S, Nantz M.: A chemoselective, one-pot transformation of aldehydes to nitriles. J. Org. Chem. 77, 9334–9337 (2012)
9. Seoudi R, El-Bahy G, El Sayed Z.: FTIR, TGA and DC electrical conductivity studies of phthalocyanine and its complexes. J. Mol. Struct. 753, 119–126 (2005)