Synthesis, Crystal Structures, and Magnetic Properties
of Two Novel Cyanido-Bridged Heterotrimetallic {Cu<sup>II</sup>Mn<sup>II</sup>Cr<sup>III</sup>} Complexes
Maria-Gabriela Alexandru
Diana Visinescu
Sergiu Shova
Marius Andruh
Francesc Lloret
Miguel Julve
10.1021/acs.inorgchem.6b02966.s002
https://acs.figshare.com/articles/dataset/Synthesis_Crystal_Structures_and_Magnetic_Properties_of_Two_Novel_Cyanido-Bridged_Heterotrimetallic_Cu_sup_II_sup_Mn_sup_II_sup_Cr_sup_III_sup_Complexes/4630327
The
self-assembly process between the heteroleptic [Cr<sup>III</sup>(phen)(CN)<sub>4</sub>]<sup>−</sup> and [Cr<sup>III</sup>(ampy)(CN)<sub>4</sub>]<sup>−</sup> metalloligands and the heterobimetallic {Cu<sup>II</sup>(valpn)Mn<sup>II</sup>}<sup>2+</sup> tecton afforded two
heterotrimetallic complexes of formula [{Cu<sup>II</sup>(valpn)Mn<sup>II</sup>(μ-NC)<sub>2</sub>Cr<sup>III</sup>(phen)(CN)<sub>2</sub>}<sub>2</sub>{(μ-NC)Cr<sup>III</sup>(phen)(CN)<sub>3</sub>}<sub>2</sub>]·2CH<sub>3</sub>CN (<b>1</b>) and {[Cu<sup>II</sup>(valpn)Mn<sup>II</sup>(μ-NC)<sub>2</sub>Cr<sup>III</sup>(ampy)(CN)<sub>2</sub>]<sub>2</sub>·2CH<sub>3</sub>CN}<sub><i>n</i></sub> (<b>2</b>) [phen = 1,10-phenanthroline, ampy = 2-aminomethylpyridine,
and H<sub>2</sub>valpn = 1,3-propanedyilbis(2-iminomethylene-6-methoxyphenol)].
The crystal structure of <b>1</b> consists of neutral Cu<sup>II</sup><sub>2</sub>Mn<sup>II</sup><sub>2</sub>Cr<sup>III</sup><sub>4</sub> octanuclear units, where two [Cr(phen)(CN)<sub>4</sub>]<sup>−</sup> anions act as bis-monodentate ligands through cyanide
groups toward two manganese(II) ions from two [Cu<sup>II</sup>(valpn)Mn<sup>II</sup>]<sup>2+</sup> units to form a [{Cu(valpn)Mn}<sub>2</sub>Cr<sub>2</sub>(CN)<sub>4</sub>]<sup>6+</sup> square motif. Two [Cr(phen)(CN)<sub>4</sub>]<sup>−</sup> pendant anions in <b>1</b> are
bound to the copper(II) ions with <i>cis–trans</i> geometry with respect to the bridging [Cr(phen)(CN)<sub>4</sub>]<sup>−</sup> anion. Compound <b>2</b> is a sheet-like coordination
polymer, where chains constituted by {Cr<sup>III</sup>(ampy)(CN)<sub>4</sub>} spacers act as bis-monodentate ligands toward the manganese(II)
ions belonging to the {Cu<sup>II</sup>(valpn)Mn<sup>II</sup>} nodes,
which are interlinked by another {Cr<sup>III</sup>(ampy)(CN)<sub>4</sub>} unit that acts as a bridge between the copper(II) and manganese(II)
ions of adjacent chains. Magnetic susceptibility measurements in the
temperature range of 1.9–300 K were performed for <b>1</b> and <b>2</b>. An overall antiferromagnetic behavior is observed
for <b>1</b>, the ground spin state being described by a spin
triplet from the square motif plus two magnetically isolated spin
triplets from the two peripheral chromium(III) ions. Ferrimagnetic
chains with interacting spins 1/2 (resulting spin of the trimetallic
{Cu<sup>II</sup>(valpn)Mn<sup>II</sup>(μ-NC)Cr<sup>III</sup>} fragment) and 3/2 (spin from the <i>bis</i>-monodentate
[Cr<sup>III</sup>(ampy)(CN)<sub>4</sub>]<sup>−</sup> with weak
interchain ferromagnetic interactions across the cyanide bridge between
the chromium(III) and the copper(II) ion from adjacent chains [θ
= +3.83(2) cm<sup>–1</sup>]) occur in <b>2</b>, resulting
into a ferromagnetic ordering below 3.5 K. The values of the magnetic
coupling between the Cu(II) and Mn(II) ions through the double phenoxide
bridge [<i>J</i> = −63.1(2) (<b>1</b>) and
−62(3) cm<sup>–1</sup> (<b>2</b>)] and those between
the Cr(III) and the Mn(II) across the single cyanide bridge [<i>J</i> = −7.08(5) and −4.86(6) cm<sup>–1</sup> (<b>1</b>) and −8.59(3) cm<sup>–1</sup> (<b>2</b>)] agree with the values reported for these exchange pathways
in other magnetostructural studies.
2017-02-08 16:23:30
Cu II 2 Mn II 2 Cr III 4 octanuclear units
2 Cr III
H 2 valpn
cyanide bridge
Cu II
Cu II Mn II Cr III
Novel Cyanido-Bridged Heterotrimetallic
Cr III
sheet-like coordination polymer
NC
CH
CN
bis-monodentate ligands
ampy
Magnetic susceptibility measurements