17 research outputs found
Carboxylate-Free Manganese(II) Phosphonate Assemblies: Synthesis, Structure, and Magnetism
The reaction of manganese(II) salts with organophosphonic
acid
[<i>t</i>-BuPO<sub>3</sub>H<sub>2</sub> or cyclopentyl phosphonic
acid (C<sub>5</sub>H<sub>9</sub>PO<sub>3</sub>H<sub>2</sub>)] in the
presence of ancillary nitrogen ligands [1,10-phenanthroline (phen)
or 2,6-bis(pyrazol-3-yl)pyridine (dpzpy)], afforded, depending on
the stoichiometry of the reactants and the reaction conditions, dinuclear,
trinuclear, and tetranuclear compounds, [Mn<sub>2</sub>(<i>t</i>-BuPO<sub>3</sub>H)<sub>4</sub>(phen)<sub>2</sub>]·2DMF (<b>1</b>), [Mn<sub>3</sub>(C<sub>5</sub>H<sub>9</sub>PO<sub>3</sub>)<sub>2</sub>(phen)<sub>6</sub>](ClO<sub>4</sub>)<sub>2</sub>·7CH<sub>3</sub>OH (<b>2</b>), [Mn<sub>3</sub>(<i>t</i>-BuPO<sub>3</sub>)<sub>2</sub>(dpzpy)<sub>3</sub>](ClO<sub>4</sub>)<sub>2</sub>·H<sub>2</sub>O (<b>3</b>), [Mn<sub>4</sub>(<i>t</i>-BuPO<sub>3</sub>)<sub>2</sub>(<i>t</i>-BuPO<sub>3</sub>H)<sub>2</sub>(phen)<sub>6</sub>(H<sub>2</sub>O)<sub>2</sub>](ClO<sub>4</sub>)<sub>2</sub> (<b>4</b>), and [Mn<sub>4</sub>(C<sub>5</sub>H<sub>9</sub>PO<sub>3</sub>)<sub>2</sub>(phen)<sub>8</sub>(H<sub>2</sub>O)<sub>2</sub>](ClO<sub>4</sub>)<sub>4</sub> (<b>5</b>). Magnetic studies on <b>1</b>, <b>2</b>, and <b>4</b> reveal that the phosphonate bridges mediate weak antiferromagnetic
interactions between the Mn<sup>II</sup> ions have also been carried
out
Carboxylate-Free Manganese(II) Phosphonate Assemblies: Synthesis, Structure, and Magnetism
The reaction of manganese(II) salts with organophosphonic
acid
[<i>t</i>-BuPO<sub>3</sub>H<sub>2</sub> or cyclopentyl phosphonic
acid (C<sub>5</sub>H<sub>9</sub>PO<sub>3</sub>H<sub>2</sub>)] in the
presence of ancillary nitrogen ligands [1,10-phenanthroline (phen)
or 2,6-bis(pyrazol-3-yl)pyridine (dpzpy)], afforded, depending on
the stoichiometry of the reactants and the reaction conditions, dinuclear,
trinuclear, and tetranuclear compounds, [Mn<sub>2</sub>(<i>t</i>-BuPO<sub>3</sub>H)<sub>4</sub>(phen)<sub>2</sub>]·2DMF (<b>1</b>), [Mn<sub>3</sub>(C<sub>5</sub>H<sub>9</sub>PO<sub>3</sub>)<sub>2</sub>(phen)<sub>6</sub>](ClO<sub>4</sub>)<sub>2</sub>·7CH<sub>3</sub>OH (<b>2</b>), [Mn<sub>3</sub>(<i>t</i>-BuPO<sub>3</sub>)<sub>2</sub>(dpzpy)<sub>3</sub>](ClO<sub>4</sub>)<sub>2</sub>·H<sub>2</sub>O (<b>3</b>), [Mn<sub>4</sub>(<i>t</i>-BuPO<sub>3</sub>)<sub>2</sub>(<i>t</i>-BuPO<sub>3</sub>H)<sub>2</sub>(phen)<sub>6</sub>(H<sub>2</sub>O)<sub>2</sub>](ClO<sub>4</sub>)<sub>2</sub> (<b>4</b>), and [Mn<sub>4</sub>(C<sub>5</sub>H<sub>9</sub>PO<sub>3</sub>)<sub>2</sub>(phen)<sub>8</sub>(H<sub>2</sub>O)<sub>2</sub>](ClO<sub>4</sub>)<sub>4</sub> (<b>5</b>). Magnetic studies on <b>1</b>, <b>2</b>, and <b>4</b> reveal that the phosphonate bridges mediate weak antiferromagnetic
interactions between the Mn<sup>II</sup> ions have also been carried
out
New Structural Form of a Tetranuclear Lanthanide Hydroxo Cluster: Dy<sub>4</sub> Analogue Display Slow Magnetic Relaxation
A series of tetranuclear lanthanide (Ln = Tb, Dy, Ho)
hydroxo clusters has been synthesized by reaction of LnCl<sub>3</sub>·6H<sub>2</sub>O (Ln = Tb (<b>1</b>), Dy (<b>2</b>), Ho (<b>3</b>)) with <i>o</i>-vanilin based schiff
base ligand 2-(2,3 dihydroxpropyl imino methyl) 6-methoxy phenol (H<sub>3</sub>L) in methanol and in the presence of triethylamine as base.
The solid state structures of all the products were established by
single crystal X-ray diffraction technique. Magnetism studies reveal
that Dy<sub>4</sub> analogue exhibits slow magnetic relaxation at
low temperatures
Two Isostructural Coordination Polymers Showing Diverse Magnetic Behaviors: Weak Coupling (Ni<sup>II</sup>) and an Ordered Array of Single-Chain Magnets (Co<sup>II</sup>)
Two isomorphic 3-D
complexes with the formulas [M<sub>3</sub>(TPTA) (OH)<sub>2</sub>(H<sub>2</sub>O)<sub>4</sub>]<sub><i>n</i></sub> (M = Ni for <b>1</b> and Co for <b>2</b>; H<sub>4</sub>TPTA = [1,1′:4′,1″-terphenyl]-2′,3,3″,5′-tetracarboxylic
acid) have been synthesized and magnetically characterized. Complexes <b>1</b> (Ni<sup>II</sup>) and <b>2</b> (Co<sup>II</sup>) have
the same 1-D rod-shaped inorganic SBUs but exhibit significantly different
magnetic properties. Complex <b>2</b>(Co<sup>II</sup>) is a
3-D arrangement of a 1-D Co<sup>II</sup> single-chain magnet (SCM),
while complex <b>1</b>(Ni<sup>II</sup>) exhibits weak coupling
Molecular [(Fe<sub>3</sub>)–(Fe<sub>3</sub>)] and [(Fe<sub>4</sub>)–(Fe<sub>4</sub>)] Coordination Cluster Pairs as Single or Composite Arrays
The synthesis of molecular cluster pairs is a challenge
for coordination
chemists due to the potential applications of these species in molecular
spintronics or quantum computing. The ligand H<sub>4</sub>L, 1,3-bis-(3-oxo-3-(2-hydroxyphenyl)-propionyl)-2-methoxybenzene,
has been successfully used to obtain a series of such complexes using
the basic Fe(III) trinuclear carboxylates as starting materials. Synthetic
control has allowed the isolation of the two molecular cluster pairs
that form the composite [Fe<sub>4</sub>O<sub>2</sub>(PhCO<sub>2</sub>)<sub>6</sub>(H<sub>2</sub>L)(pz)]<sub>2</sub>[Fe<sub>3</sub>O(PhCO<sub>2</sub>)<sub>5</sub>(py)(H<sub>2</sub>L)]<sub>2</sub> (<b>1</b>). The dimers of trinuclear units, [Fe<sub>3</sub>O(PhCO<sub>2</sub>)<sub>5</sub>(H<sub>2</sub>O)(H<sub>2</sub>L)]<sub>2</sub> (<b>2</b>) and [Fe<sub>3</sub>O(<i>o</i>-MePhCO<sub>2</sub>)<sub>5</sub>(H<sub>2</sub>L)(py)]<sub>2</sub> (<b>3</b>),
and the dimers of tetranuclear units, [Fe<sub>4</sub>O<sub>2</sub>(PhCO<sub>2</sub>)<sub>6</sub>(H<sub>2</sub>L)(pz)]<sub>2</sub> (<b>4</b>) and [Fe<sub>4</sub>O<sub>2</sub>(<i>o</i>–MePhCO<sub>2</sub>)<sub>6</sub>(H<sub>2</sub>L)(pz)]<sub>2</sub> (<b>5</b>), are presented here. The magnetic properties of the reported aggregates
show that they are pairs of semi-independent clusters weakly interacting
magnetically as required for two-qubit quantum gates
Molecular [(Fe<sub>3</sub>)–(Fe<sub>3</sub>)] and [(Fe<sub>4</sub>)–(Fe<sub>4</sub>)] Coordination Cluster Pairs as Single or Composite Arrays
The synthesis of molecular cluster pairs is a challenge
for coordination
chemists due to the potential applications of these species in molecular
spintronics or quantum computing. The ligand H<sub>4</sub>L, 1,3-bis-(3-oxo-3-(2-hydroxyphenyl)-propionyl)-2-methoxybenzene,
has been successfully used to obtain a series of such complexes using
the basic Fe(III) trinuclear carboxylates as starting materials. Synthetic
control has allowed the isolation of the two molecular cluster pairs
that form the composite [Fe<sub>4</sub>O<sub>2</sub>(PhCO<sub>2</sub>)<sub>6</sub>(H<sub>2</sub>L)(pz)]<sub>2</sub>[Fe<sub>3</sub>O(PhCO<sub>2</sub>)<sub>5</sub>(py)(H<sub>2</sub>L)]<sub>2</sub> (<b>1</b>). The dimers of trinuclear units, [Fe<sub>3</sub>O(PhCO<sub>2</sub>)<sub>5</sub>(H<sub>2</sub>O)(H<sub>2</sub>L)]<sub>2</sub> (<b>2</b>) and [Fe<sub>3</sub>O(<i>o</i>-MePhCO<sub>2</sub>)<sub>5</sub>(H<sub>2</sub>L)(py)]<sub>2</sub> (<b>3</b>),
and the dimers of tetranuclear units, [Fe<sub>4</sub>O<sub>2</sub>(PhCO<sub>2</sub>)<sub>6</sub>(H<sub>2</sub>L)(pz)]<sub>2</sub> (<b>4</b>) and [Fe<sub>4</sub>O<sub>2</sub>(<i>o</i>–MePhCO<sub>2</sub>)<sub>6</sub>(H<sub>2</sub>L)(pz)]<sub>2</sub> (<b>5</b>), are presented here. The magnetic properties of the reported aggregates
show that they are pairs of semi-independent clusters weakly interacting
magnetically as required for two-qubit quantum gates
Molecular [(Fe<sub>3</sub>)–(Fe<sub>3</sub>)] and [(Fe<sub>4</sub>)–(Fe<sub>4</sub>)] Coordination Cluster Pairs as Single or Composite Arrays
The synthesis of molecular cluster pairs is a challenge
for coordination
chemists due to the potential applications of these species in molecular
spintronics or quantum computing. The ligand H<sub>4</sub>L, 1,3-bis-(3-oxo-3-(2-hydroxyphenyl)-propionyl)-2-methoxybenzene,
has been successfully used to obtain a series of such complexes using
the basic Fe(III) trinuclear carboxylates as starting materials. Synthetic
control has allowed the isolation of the two molecular cluster pairs
that form the composite [Fe<sub>4</sub>O<sub>2</sub>(PhCO<sub>2</sub>)<sub>6</sub>(H<sub>2</sub>L)(pz)]<sub>2</sub>[Fe<sub>3</sub>O(PhCO<sub>2</sub>)<sub>5</sub>(py)(H<sub>2</sub>L)]<sub>2</sub> (<b>1</b>). The dimers of trinuclear units, [Fe<sub>3</sub>O(PhCO<sub>2</sub>)<sub>5</sub>(H<sub>2</sub>O)(H<sub>2</sub>L)]<sub>2</sub> (<b>2</b>) and [Fe<sub>3</sub>O(<i>o</i>-MePhCO<sub>2</sub>)<sub>5</sub>(H<sub>2</sub>L)(py)]<sub>2</sub> (<b>3</b>),
and the dimers of tetranuclear units, [Fe<sub>4</sub>O<sub>2</sub>(PhCO<sub>2</sub>)<sub>6</sub>(H<sub>2</sub>L)(pz)]<sub>2</sub> (<b>4</b>) and [Fe<sub>4</sub>O<sub>2</sub>(<i>o</i>–MePhCO<sub>2</sub>)<sub>6</sub>(H<sub>2</sub>L)(pz)]<sub>2</sub> (<b>5</b>), are presented here. The magnetic properties of the reported aggregates
show that they are pairs of semi-independent clusters weakly interacting
magnetically as required for two-qubit quantum gates
Molecular [(Fe<sub>3</sub>)–(Fe<sub>3</sub>)] and [(Fe<sub>4</sub>)–(Fe<sub>4</sub>)] Coordination Cluster Pairs as Single or Composite Arrays
The synthesis of molecular cluster pairs is a challenge
for coordination
chemists due to the potential applications of these species in molecular
spintronics or quantum computing. The ligand H<sub>4</sub>L, 1,3-bis-(3-oxo-3-(2-hydroxyphenyl)-propionyl)-2-methoxybenzene,
has been successfully used to obtain a series of such complexes using
the basic Fe(III) trinuclear carboxylates as starting materials. Synthetic
control has allowed the isolation of the two molecular cluster pairs
that form the composite [Fe<sub>4</sub>O<sub>2</sub>(PhCO<sub>2</sub>)<sub>6</sub>(H<sub>2</sub>L)(pz)]<sub>2</sub>[Fe<sub>3</sub>O(PhCO<sub>2</sub>)<sub>5</sub>(py)(H<sub>2</sub>L)]<sub>2</sub> (<b>1</b>). The dimers of trinuclear units, [Fe<sub>3</sub>O(PhCO<sub>2</sub>)<sub>5</sub>(H<sub>2</sub>O)(H<sub>2</sub>L)]<sub>2</sub> (<b>2</b>) and [Fe<sub>3</sub>O(<i>o</i>-MePhCO<sub>2</sub>)<sub>5</sub>(H<sub>2</sub>L)(py)]<sub>2</sub> (<b>3</b>),
and the dimers of tetranuclear units, [Fe<sub>4</sub>O<sub>2</sub>(PhCO<sub>2</sub>)<sub>6</sub>(H<sub>2</sub>L)(pz)]<sub>2</sub> (<b>4</b>) and [Fe<sub>4</sub>O<sub>2</sub>(<i>o</i>–MePhCO<sub>2</sub>)<sub>6</sub>(H<sub>2</sub>L)(pz)]<sub>2</sub> (<b>5</b>), are presented here. The magnetic properties of the reported aggregates
show that they are pairs of semi-independent clusters weakly interacting
magnetically as required for two-qubit quantum gates
Two New Coordination Polymers with Co(II) and Mn(II): Selective Gas Adsorption and Magnetic Studies
A novel bifurcated ligand 3,5-di(1<i>H</i>-benzo[<i>d</i>]imidazol-1-yl)benzonitrile (DBIBN) has been synthesized,
which reacts with Co(II) and Mn(II) salts to form new coordination
polymers {[Co<sub>2</sub>(DBIBA)<sub>3</sub>]·Cl·9H<sub>2</sub>O}<sub><i>n</i></sub> (<b>1</b>) and {[Mn<sub>3</sub>(DBIBA)<sub>6</sub>]}<sub><i>n</i></sub> (<b>2</b>), (DBIBA = 3,5-di(1<i>H</i>-benzo[d]imidazol-1-yl)benzoate),
in which DBIBN get hydrolyzed into DBIBA under solvothermal conditions.
Both the complexes have been
characterized by single-crystal X-ray crystallography (XRD), IR spectroscopy,
elemental analysis, thermogravimetry, and X-ray powder diffraction
(PXRD). Complex <b>1</b> is a 3D coordination polymer composed
of binuclear Co(II) units, having (4,6) connected net. On the other
hand, complex <b>2</b> is a layered structure with trinuclear
Mn(II) units, which has 4-connected 4<sup>4</sup> <i><b>sql</b></i> topology. TGA and PXRD measurements show that the framework <b>1</b> is stable after desolvation. Desolvated framework <b>1</b> showed selective adsorption of CO<sub>2</sub> over N<sub>2</sub>, H<sub>2,</sub> and Ar. Variable temperature magnetic susceptibility
measurements show that complex <b>1</b> exhibits weak antiferromagnetic
behavior
Gas Adsorption, Magnetism, and Single-Crystal to Single-Crystal Transformation Studies of a Three-Dimensional Mn(II) Porous Coordination Polymer
A porous coordination polymer {[Mn<sub>2</sub>(DBIBA)<sub>3</sub>]NO<sub>3</sub>·3DMF·4H<sub>2</sub>O}<sub><i>n</i></sub> (<b>1</b>) [DBIBAH =
3,5-di(1<i>H</i>-benzo[d]imidazol-1-yl)benzoic
acid] has been synthesized
solvothermally and structurally characterized by single-crystal X-ray
diffraction. The following four new coordination polymers {[Mn<sub>2</sub>(DBIBA)<sub>3</sub>]·ClO<sub>4</sub>·DMF·H<sub>2</sub>O}<sub><i>n</i></sub> (<b>2</b>), {[Mn<sub>2</sub>(DBIBA)<sub>3</sub>]·Cl·DMF·8H<sub>2</sub>O}<sub><i>n</i></sub> (<b>3</b>), {[Mn<sub>2</sub>(DBIBA)<sub>3</sub>]·NO<sub>3</sub>·CH<sub>3</sub>OH·5H<sub>2</sub>O}<sub><i>n</i></sub> (<b>4</b>) and {[Mn<sub>2</sub>(DBIBA)<sub>3</sub>]·NO<sub>3</sub>·3CH<sub>3</sub>COCH<sub>3</sub>·7H<sub>2</sub>O}<sub><i>n</i></sub> (<b>5</b>) have been
synthesized from <b>1</b> via anion/solvent exchange protocols
in a single-crystal to single-crystal fashion at room temperature.
Gas sorption studies for desolvated compounds <b>1</b>, <b>2</b>, and <b>3</b> show that CO<sub>2</sub> uptake capacity
is entirely dependent upon the size of the anion present in the framework.
Complex <b>1</b> also exhibits antiferromagnetic properties
below 17 K, confirmed through magnetic susceptibility measurements