Authors Research group(s) Collaborations

Thematic StrandAdvanced Materials

Funding

Thematic StrandEnvironment & Cultural Heritage

Lanthanide based Materialsin Spintronics, Environmental

and Sensor Applications

First example of an observable and reversible case of thermochromism due to the interaction of an alkylphosphonium [P6,6,6,14]+ with aβ-diketonate of the room temperature ionic liquid (RTIL) [P6,6,6,14][Eu(fod)4] (1).

Single Molecule Magnets (SMMs) have several potential applications but the blocking temperatures (TB) of SMMs need to be considerably improved. As so, fundamental knowledge in understanding the principlesbehind SMMs is still required in order to obtain increases in TB values, hopefully to liquid nitrogen temperatures and beyond. In an ongoing work we describe an experimental and theoretical study of the magneticproperties of LLHs materials (Ln8(OH)20Cl4•6H2O, Ln = Dy, Tb, Ho, Er), both diluted in the diamagnetic Y analogous matrix and intercalated with a large anion (2,6-naphtalene dicarboxylate).

• Societal challenge “Climate action, environment, resource efficiency and raw materials”• Societal challenge “Food security, sustainable agriculture and forestry, marine and maritime and inland water research, (…)”

• Societal challenge “Food security, (…)”

• Societal challenge “Secure, clean and efficient energy”• Societal challenge “Climate action, environment, resource efficiency and raw materials”

• Molecular magnetism, molecular spintronics, quantum computing

Backcover Picture:Chem. Commun., 2017, 53, 850-853.

By changing the ligands of the Eu(II) complex with dibenzoylmethanate (dbm) we prepared the RTIL [P6,6,6,14][Eu(fod)3(dbm)] (2), while calorimetric measurements showed a melting point at 415 K for [P6,6,6,14][Eu(dbm)4](3). The luminescence quantum yields determined for 1, 2, and 3 are, 34%, 59 %, and 64 % respectively, with the highest values being comparable with the maximum values reported for complexes of the same type

Alcohol Optical Sensor

Structure of [P6,6,6,14][Eu(fod)4] formed at 80 ºC.Pictures were taken under daylight (left) and

under 366 nm UV irradiation (right).

Using only the organic moieties from compound 1 we prepared the RTIL [P6,6,6,14][fod].

Heating the ionic liquid [P6,6,6,14][fod] at 80 ºCthe solvatochromic keto-phosphorane likecompound P6,6,6,14fod is formed.

Non alcohols:Acetonitrile

Dichloromethane

Alcohols:MethanolEthanol

Sensor mechanism: The reddish P6,6,6,14fodwhen solvated by alcohol molecules turnsyellow, returning to reddish upon driyng.

KeywordsLayered Lanthanide Hydroxides

Single Molecule MagnetsPhosphorus Remediation

Optical SensorsNanomaterials

Problems addressed: the urgency, of building efficient and low cost anion sensors/scavengers for phosphate, arises fromthe heavy use of phosphate as a where 70−80% of applied phosphorus is lost and accumulates in nature. Also, phosphorusis one of the major nutrients contributing to eutrophication of rivers and lakes. Production of phosphate rock is predicted toreach its peak possibly as early as the next few decades, despite its growing demand. Industrially recovered phosphateneeds to be purified in a costly process with treatments not suitable for rural areas where the building costs andmaintenance of wastewater treatment plants would be too high. The only validated method for measuring solublephosphate in water is a colourimetric technique from the 1960s difficult to adapt for on-line measurements. Phosphateanion’s lack of electrochemical activity, together with its high hydration energy, make direct detection and transductionchallenging.

LEuH material intercalated with 2,6-naphtalene dicarboxilate,LEuH-2,6-NDC, acts as a dual-channel sensor towards anions. Thesensor was tested with several biological relevant anions showinghigh selectivity towards phosphate

LEuH, Eu8(OH)20Cl4•6H2O, presents high phosphatesequestration capacity followed by controlled release ofphosphate with improved adsorbant stability.

Adsorption procedure

100 mL water-batch experimentspH ≈ 7< 200 rpm shaking , 24 h0.030 g of LEuH ([LEuH] = 300 mgL-1)0.01735 g of Na2HPO4•12H2O ([P] = 15 mgL-1)

24 mg of P/ 1 g of LEuH

Desorption procedure

100 mL water-batch experiments< 200 rpm shaking , 24 h[NaOH] = 1 M[NaCl] = 1 M

60 % desorption

ILs were immobilized into 3D MOFs, and these composites were incorporated in a polymer matrix to yield [IL@MOF]@Matrimid®5218. This methodproved to be an efficient strategy to improve the permeability and selectivity toward mixtures of CO2/N2, presenting also a remarkableimprovement in membrane flexibility and mechanical resistance.

IL@MOF

[EMIM][CN3]

Ionic Liquids

[TMG][N3]

This is one of the very few studies reporting dramatic enhancement of IL@MOF inrespect to CO2/N2 separation. Although the Robeson´s upper bound was notsurpassed, we confirmed that this method is an excellent approach to surpass thislimit even with a very low upload of IL@MOF composite. This work clearly showsthat the careful design and selection of the structures of IL and MOFs is crucial toobtain a membrane with simultaneously high permeability and high selectivity.

LLH unit cell viewed down the (a) c axis, (b) b axis, and (c) a axis.

Theor. calc. by the REC model:

Dy1 Dy2 Dy3 grounddublet

0.76 |±13/2> 0.98 |±15/2> 0.99 |±15/2>

gz 16.2 19.79 19.91

2 coordination geometries[Dy(OH)7(H2O)] dodecahedron polyhedron

[Dy(OH)8(H2O) ] monocapped square antiprism

The experimental results, supported by theoretical calculations,put separately into evidence and explained the single ion, 2D and3D Ln-Ln interaction effects. This was the first time that such aclear separation and detailed analysis has been achieved in alayered lanthanide compound, and LDyH was the first example ofSMM behavior in a layered rare earth compound and the first LnSMM with more than 12 metal ions.

Claudia C.L. Pereira4,1, César A.T. Laia4, João C. Lima4, Artur J.Moro4, Jose J. Baldoví5, Eugenio Coronado5, Alejandro Gaita-Arino5

PSCG | Photochemistry and Supramolecular Chemistry Group,Department of Chemistry, Faculdade de Ciências e Tecnologiada Universidade Nova de Lisboa, PortugalMMRT | Molecular Materials Research Team, Instituto deCiencia Molecular, Universitat de València, Spain.

1 RS | Radiopharmaceutical Sciences Group2 RPS | Radiation Protection and Safety Group3 REI | Radiation, Elements and Isotopes Group4 NET | Nuclear Engineering and Techniques Group5 QEf | f-element Chemistry Group6 SS | Solid State Group

C2TN members: Bernardo Monteiro5,*, JoaquimMarçalo5, João P. Leal,5 Joana T. Coutinho 6, LauraC.J. Pereira6, Manuel Almeida6, Maria H. Casimiro3,Luis M. Ferreira3

http://c2tn.tecnico.ulisboa.ptRADIATION FOR SCIENCE AND SOCIETY

C2TN/IST acknowledgesFundação para a Ciência e a Tecnologia for

financial support under the projectUID/Multi/04349/2013