Triclinic La7Zn2P11 with P3-, P24-, and P35- units: a combined study by 31P solid-state NMR spectroscopy and single crystal X-ray diffraction.
KÖSTERS, Jutta; BENNDORF, Christopher; UESBECK, Tobias; WIEGAND, Thomas; ECKERT, Hellmut; LINCKE, Hannes; PÖTTGEN, Rainer.
KÖSTERS, Jutta; BENNDORF, Christopher; UESBECK, Tobias; WIEGAND, Thomas; ECKERT, Hellmut; LINCKE, Hannes; PÖTTGEN, Rainer.
Abstract: The ternary polyphosphide La7Zn2P11 was synthesized from the elements by using a salt flux or via a ceramic method in sealed quartz ampoules. The obtained samples were investigated by X-ray powder and single crystal diffraction: own type, P[1 with combining macron], a = 775.33(13), b = 827.45(13), c = 1502.8(3) pm, a = 82.111(3), ß = 77.034(3), ? = 89.996(3)°, wR2 = 0.1553, 5852 F2 values and 183 variables. This peculiar structure is characterized by the simultaneous presence of three distinct anionic phosphide species, namely P3-, P24-, and P35- units. La7Zn2P11 is an electron precise Zintl phase: (7La3+)21+(2Zn2+)4+(4P3-)12-(2P24-)8-(P35-). The P?P single bond distances range from 219.2 to 223.0 pm. The zinc sites show tetrahedral phosphorus coordination by three P3- and one P24- species. The tetrahedra are condensed to chains via common corners. The P35- units with P-P-P angles of 113.7° have exclusively lanthanum coordination. 31P solid-state NMR was used to probe the phosphorus local environments, connectivities and spatial proximities. The eleven crystallographically distinct phosphorus atoms were assigned with the help of two-dimensional homonuclear dipolar correlation experiments. Even though the application of 2D measurements on such phosphorus-based polyanionic compounds is exceedingly challenging because of the wide dispersion of chemical shifts, the fast irreversible decay of the transverse magnetization, and slow spin?lattice relaxation, a complete assignment is possible using radiofrequency-driven dipolar recoupling (RFDR), J-RESOLVED and total-through-bond correlation with R-sequence (R-TOBSY) techniques.
@article={003192273,author = {KÖSTERS, Jutta; BENNDORF, Christopher; UESBECK, Tobias; WIEGAND, Thomas; ECKERT, Hellmut; LINCKE, Hannes; PÖTTGEN, Rainer.},title={Triclinic La7Zn2P11 with P3-, P24-, and P35- units: a combined study by 31P solid-state NMR spectroscopy and single crystal X-ray diffraction},journal={Dalton Transactions},note={v. 53, n. 15, p. 6720-6730},year={2024}}