ic6b00736_si_005.cif (18 kB)
Ammonothermal Synthesis, Crystal Structure, and Properties of the Ytterbium(II) and Ytterbium(III) Amides and the First Two Rare-Earth-Metal Guanidinates, YbC(NH)3 and Yb(CN3H4)3
dataset
posted on 2016-06-01, 19:03 authored by Arno L. Görne, Janine George, Jan van Leusen, Gerald Dück, Philipp Jacobs, Naveen Kumar Chogondahalli
Muniraju, Richard DronskowskiWe
report the oxidation-controlled synthesis of the ytterbium amides
Yb(NH2)2 and Yb(NH2)3 and
the first rare-earth-metal guanidinates YbC(NH)3 and Yb(CN3H4)3 from liquid ammonia. For Yb(NH2)2, we present experimental atomic displacement
parameters from powder X-ray diffraction (PXRD) and density functional
theory (DFT)-derived hydrogen positions for the first time. For Yb(NH2)3, the indexing proposal based on PXRD arrives
at R3̅, a = 6.2477(2) Å, c = 17.132(1) Å, V = 579.15(4) Å3, and Z = 6. The oxidation-controlled synthesis
was also applied to make the first rare-earth guanidinates, namely,
the doubly deprotonated YbC(NH)3 and the singly deprotonated
Yb(CN3H4)3. YbC(NH)3 is
isostructural with SrC(NH)3, as derived from PXRD (P63/m, a =
5.2596(2) Å, c = 6.6704(2) Å, V = 159.81(1) Å3, and Z = 2). Yb(CN3H4)3 crystallizes in a structure derived
from the [ReO3] type, as studied by powder neutron diffraction
(Pn3̅, a = 13.5307(3) Å, V = 2477.22(8) Å3, and Z = 8 at 10 K). Electrostatic and hydrogen-bonding interactions cooperate
to stabilize the structure with wide and empty channels. The IR spectra
of the guanidinates are compared with DFT-calculated phonon spectra
to identify the vibrational modes. SQUID magnetometry shows that Yb(CN3H4)3 is a paramagnet with isolated Yb3+ (4f13) ions. A CONDON 2.0 fit
was used to extract all relevant parameters.