X‐ray Diffraction and Solid‐State NMR Studies of a Germanium Binuclear Complex

Abstract

A compound formulated as (C4H12N2)[Ge2(pmida)2(OH)2] x 4 H2O (where pmida(4-) = N-(phosphonomethyl)iminodiacetate and C4H12N2(2+) = piperazinedium cation), containing the anionic [Ge2(pmida)2(OH)2]2- complex, has been synthesised by the hydrothermal approach and its structure determined by single-crystal X-ray diffraction analysis. Several high-resolution solid-state magic-angle spinning (MAS) NMR techniques, in particular two-dimensional 1H-X(13C,31P) heteronuclear correlation (HETCOR) and 1H-1H homonuclear correlation (HOMCOR) experiments incorporating a frequency-switched Lee-Goldburg (FS-LG) decoupling scheme, have been employed for the first time in such a material. Using these tools in tandem affords an excellent general approach to study the structure of other inorganic-organic hybrids. We assigned the NMR resonances with the help of C...H and P...H internuclear distances obtained through systematic statistical analyses of the crystallographic data. The compound was further characterised by powder X-ray diffraction techniques, IR and Raman spectroscopy, and by elemental and thermal analyses (thermogravimetric analysis and differential scanning calorimetry).

Synthetic, structural and solution speciation studies on binary Al(III)–(carboxy)phosphonate systems. Relevance to the neurotoxic potential of Al(III)

“…The resonances at 56.3 and 57.8 ppm were attributed to the C(5) carbon of the phosphonate CH 2 group, with the splitting of $150 Hz due to the 1 J-coupling interaction ( 1 J C(1),P(1) ), as confirmed by the 13 C NMR spectra of 1. The corresponding interaction of the free NTAP ligand is 1 J C(1),P(1) = 146 Hz, in line with literature [58]. The peaks at 59.5 and 66.6 ppm were attributed to the C(2) and C(4) carbons of the CH 2 groups of the carboxylates, which are both bound to the central Al(III) ion.…”

“…The two resonance lines in the low field region (174.9 ppm and 179.9 ppm) are attributed to the C(1) and C(3) carbons of the carboxylate groups bound to the Al(III) center. The signals are shifted 5.7 ppm and 13.5 ppm, respectively, to lower fields in comparison to the corresponding signal of the free NTAP ligand [58]. The 31 P CP-MAS-NMR spectrum of 1 (Fig.…”

Crystal Structure, Solid‐State NMR Spectroscopic and Photoluminescence Studies of Organic‐Inorganic Hybrid Materials (HL)6[Ge6(OH)6(hedp)6]·2(L)·nH2O, L = hqn or phen

“…[21,[23][24][25][26] However, advanced 1 H NMR techniques have been much less applied to the study of complex inorganic-hybrid materials. [27][28][29] Here, we wish to report the synthesis, single-crystal structure and photoluminescence properties of two germaniumhedp 4-solids with heteroaromatic amines 8-hydroxyquinoline and 1,10-phenanthroline, (HL) 6 [Ge 6 (OH) 6 (hedp) 6 ]·2(L)· nH 2 O (L = hqn or phen), in I and II, respectively, which are involved in columnar π-π stacking interactions and exhibit complex hydrogen-bond networks. The materials have been further characterised by elemental analysis, thermogravimetry and FTIR, Raman and UV/Vis spectroscopy.…”

Practical aspects of Lee–Goldburg based CRAMPS techniques for high-resolution 1H NMR spectroscopy in solids: Implementation and applications

“…The simple LG decoupling has been also employed to aid in the measurement of 1 H-X dipolar couplings and to amplify the magnitude in the CSA of X nuclei [30,31]. FSLG and PMLG blocks have been successfully inserted during the t 1 evolution, in order to obtain a high-resolution 1 H spectra in the indirect dimension in 2D HOMCOR [16,[32][33][34] and CP HETCOR [14,16,[33][34][35][36][37].…”