GAS PHASE F-ELEMENT CHEMISTRY Sc2tn.tecnico.ulisboa.pt/images/2nd_c2tn_workshop/posters/Posters -...
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RADIATION FOR SCIENCE AND SOCIETY Keywords “Ion Chemistry” “Mass Spectrometry” “Uranium Oxide Clusters” “Praseodymium(V)” “Hydrocarbon Activation” C 2 TN members: Joaquim Marçalo 1 *, Bernardo Monteiro 1 (IST-ID Contract), João P. Leal 1 , Joaquim B. Branco 1 , José M. Carretas 1 , Leonor Maria 1 (IST-ID Contract) * Email of corresponding author: [email protected] Collaborations 1 John K. Gibson | Lawrence Berkeley National Laboratory, Berkeley, USA 2 Nuno A. G. Bandeira | BioISI - FCUL, Lisboa, Portugal Funding GAS-PHASE F-ELEMENT CHEMISTRY S TUDIES Thematic Strands Earth Systems, Radioactivity and Cultural Heritage Advanced Materials C 2 TN/IST acknowledges the financial support under the project UID/Multi/04349/2013 http://c2tn.tecnico.ulisboa.pt Introduction For some years, we have been using FTICR and QIT mass spectrometry to examine the gas-phase ion chemistry of the lanthanides from La to Lu (except Pm) and the actinides from Th to Cm. We have revealed new f- element species, determined thermodynamic properties of neutral and ionic molecules, and, in the case of the actinides, probed the role of 5f electrons in bonding and the issue of covalence. These studies have a fundamental nature and do not address UN’s Sustainable Development Goals directly. Nonetheless, we expect to continue participating in the progress of f-element chemistry and, therefore, contribute to the resolution of “Energy” and “Environment” concerns. Reactivity of uranium oxide cluster anions with methanol Fig. 3 - LDI(-) mass spectrum of UO 3 . 1. [U 2 O 6 ] - + CH 3 OH [U 2 O 5 (OH)(OCH 3 )] - 2. [U 2 O 5 (OH)(OCH 3 )] - + CH 3 OH [U 2 O 5 (OCH 3 ) 2 ] - + H 2 O 3. [U 2 O 5 (OCH 3 ) 2 ] - + CH 3 OH [U 2 O 4 (OH)(OCH 3 ) 3 ] - 4. [U 2 O 4 (OH)(OCH 3 ) 3 ] - + CH 3 OH [U 2 O 4 (OCH 3 ) 4 ] - + H 2 O 5. [U 2 O 4 (OCH 3 ) 4 ] - + CH 3 OH [U 2 O 3 (OH)(OCH 3 ) 5 ] - 6. [U 2 O 3 (OH)(OCH 3 ) 5 ] - + CH 3 OH [U 2 O 3 (OCH 3 ) 6 ] - + H 2 O U 2 O 6 - ,U 3 O 8 - and U 3 O 9 - react sequentially with six molecules of methanol, by alternate methanol addition and methanol addition plus water elimination, to form uranium oxide cluster ions with six coordinated methoxides. These results can be directly compared with the reaction of methanol at uranium oxide solid surfaces, where the initial step is methoxide formation. Activation of hydrocarbons by rare earth, thorium and uranium oxide-nitrate anions CID of metal nitrate anions in the presence of ethane, ethene and benzene show the formation of alkoxide and phenoxide species, resulting from hydrocarbon activation by oxide anions containing a radical oxygen. These experimental studies bear interest in the long-standing search for systems that are capable of activating methane. Fig. 8 – Mass spectrum showing activation of ethene by [LaO(NO 3 ) 3 ] - during CID of [La(NO 3 ) 4 ] - . Probing a rare high oxidation state in the lanthanide series - Pr(V) [CeO 2 (NO 3 ) 2 ] - + H 2 O ––> [CeO(OH)(NO 3 ) 2 ] - + OH [PrO 2 (NO 3 ) 2 ] - + H 2 O ––> NO REACTION [NdO 2 (NO 3 ) 2 ] - + H 2 O ––> [NdO 2 (H 2 O)(NO 3 ) 2 ] - The hydrolysis behavior of [LnO 2 (NO 3 ) 2 ] - ions for Ln = Ce, Pr and Nd are related to the relative stability of the Ln oxidation states (OS). These results confirm that Pr(V) is readily accessible and that high OS lanthanide chemistry could be richer than previously assumed. Fig. 7 – Most stable structures of the [LnO 2 (NO 3 ) 2 ] - complexes for Ln = Ce, Pr and Nd. Ce IV Pr V Nd III Fig. 6 – Mass spectra showing the formation of [Pr V O 2 (NO 3 ) 2 ] - and its stability towards water. Fig. 9 – Activation of ethene by [MO(NO 3 ) 3 ]-. [MO(NO 3 ) 3 ] - + RH ––> [M(OR)(NO 3 ) 3 ] - + H [ThO(NO 3 ) 4 ] - + RH ––> [Th(OR)(NO 3 ) 4 ] - + H [UO 2 (O 2 )(NO 3 )] - + RH ––> [UO 2 (O)(OR)(NO 3 )] - + H (M = Sc, Y, Ln; RH = ethane, ethene, benzene) Fig. 4 – Mass spectrum of the reaction of U 2 O 6 - with CD 3 OH (delay 1 s). Fig. 5 - Suggested overall reaction of U 2 O 6 - with methanol. Reference : [1] Marçalo, J.; Gibson, J. K. “Gas-Phase Ion Chemistry of Rare Earths and Actinides”, in Handbook on the Physics and Chemistry of Rare Earths (Including Actinides), Bünzli, J.-C. G.; Pecharsky,V. K. (Eds.), Elsevier, Amsterdam, 2014, Vol. 45, pp. 1–110. Results and discussion Experimental details The FTICR-MS experiments were performed in an Extrel/Finnigan FTMS 2001-DT 3 Tesla instrument (Fig. 1), coupled to a Nd:YAG laser (1064 nm) for laser desorption/ionization (LDI). The QIT-MS experiments were performed in a Bruker HCT instrument (Fig. 2) equipped with an electrospray ionization (ESI) source. Fig. 1 – FTICR mass spectrometer. Fig. 2 – QIT mass spectrometer. Research group 1 QEf | f-element Chemistry Group
Transcript of GAS PHASE F-ELEMENT CHEMISTRY Sc2tn.tecnico.ulisboa.pt/images/2nd_c2tn_workshop/posters/Posters -...
RADIATION FOR SCIENCE AND SOCIETY
Keywords“Ion Chemistry”
“Mass Spectrometry”“Uranium Oxide
Clusters”“Praseodymium(V)”
“Hydrocarbon Activation”
C2TN members: Joaquim Marçalo1*, Bernardo Monteiro1 (IST-ID Contract), João P. Leal1, Joaquim B. Branco1, José M. Carretas1, Leonor Maria1 (IST-ID Contract)* Email of corresponding author: [email protected]
Collaborations1 John K. Gibson | Lawrence Berkeley National Laboratory, Berkeley, USA2 Nuno A. G. Bandeira | BioISI - FCUL, Lisboa, Portugal
Funding
GAS-PHASE F-ELEMENT CHEMISTRY STUDIES
Thematic Strands
Earth Systems, Radioactivity and Cultural Heritage Advanced Materials
C2TN/IST acknowledges the financial supportunder the project UID/Multi/04349/2013
http://c2tn.tecnico.ulisboa.pt
IntroductionFor some years, we have been using FTICR and QIT mass spectrometryto examine the gas-phase ion chemistry of the lanthanides from La to Lu(except Pm) and the actinides from Th to Cm. We have revealed new f-element species, determined thermodynamic properties of neutral andionic molecules, and, in the case of the actinides, probed the role of 5felectrons in bonding and the issue of covalence. These studies have afundamental nature and do not address UN’s Sustainable DevelopmentGoals directly. Nonetheless, we expect to continue participating in theprogress of f-element chemistry and, therefore, contribute to theresolution of “Energy” and “Environment” concerns.
Reactivity of uranium oxide cluster anions with methanol
Fig. 3 - LDI(-) mass spectrum of UO3.
1. [U2O6]- + CH3OH [U2O5(OH)(OCH3)]-
2. [U2O5(OH)(OCH3)]- + CH3OH [U2O5(OCH3)2]- + H2O3. [U2O5(OCH3)2]- + CH3OH [U2O4(OH)(OCH3)3]-
4. [U2O4(OH)(OCH3)3]- + CH3OH [U2O4(OCH3)4]- + H2O5. [U2O4(OCH3)4]- + CH3OH [U2O3(OH)(OCH3)5]-
6. [U2O3(OH)(OCH3)5]- + CH3OH [U2O3(OCH3)6]- + H2O
U2O6-, U3O8
- and U3O9- react sequentially with six
molecules of methanol, by alternate methanoladdition and methanol addition plus waterelimination, to form uranium oxide cluster ionswith six coordinated methoxides. These resultscan be directly compared with the reaction ofmethanol at uranium oxide solid surfaces, wherethe initial step is methoxide formation.
Activation of hydrocarbons by rare earth, thorium and uranium
oxide-nitrate anions
CID of metal nitrate anions in thepresence of ethane, ethene andbenzene show the formation ofalkoxide and phenoxide species,resulting from hydrocarbon activationby oxide anions containing a radicaloxygen. These experimental studiesbear interest in the long-standingsearch for systems that are capable ofactivating methane.
Fig. 8 – Mass spectrum showing activation of ethene by [LaO(NO3)3]- during CID of [La(NO3)4]-.
Probing a rare high oxidation state in the lanthanide series - Pr(V)
[CeO2(NO3)2]- + H2O ––> [CeO(OH)(NO3)2]- + OH
[PrO2(NO3)2]- + H2O ––> NO REACTION[NdO2(NO3)2]- + H2O ––> [NdO2(H2O)(NO3)2]-
The hydrolysis behavior of [LnO2(NO3)2]- ionsfor Ln = Ce, Pr and Nd are related to therelative stability of the Ln oxidation states(OS). These results confirm that Pr(V) isreadily accessible and that high OSlanthanide chemistry could be richer thanpreviously assumed.
Fig. 7 – Most stable structures of the [LnO2(NO3)2]-
complexes for Ln = Ce, Pr and Nd.
CeIV
PrV
NdIII
Fig. 6 – Mass spectra showing the formation of [PrVO2(NO3)2]- and its stability towards water.
Fig. 9 – Activation of ethene by [MO(NO3)3]-.
[MO(NO3)3]- + RH ––> [M(OR)(NO3)3]- + H
[ThO(NO3)4]- + RH ––> [Th(OR)(NO3)4]- + H
[UO2(O2)(NO3)]- + RH ––> [UO2(O)(OR)(NO3)]- + H
(M = Sc, Y, Ln; RH = ethane, ethene, benzene)
Fig. 4 – Mass spectrum of the reaction of U2O6
- with CD3OH (delay 1 s).
Fig. 5 - Suggested overall reaction of U2O6- with methanol.
Reference: [1] Marçalo, J.; Gibson, J. K. “Gas-Phase Ion Chemistry of Rare Earths and Actinides”, in Handbook on the Physics and Chemistry of Rare Earths (Including Actinides),Bünzli, J.-C. G.; Pecharsky, V. K. (Eds.), Elsevier, Amsterdam, 2014, Vol. 45, pp. 1–110.
Results and discussion
Experimental detailsThe FTICR-MS experiments were performed in an Extrel/FinniganFTMS 2001-DT 3 Tesla instrument (Fig. 1), coupled to a Nd:YAG laser(1064 nm) for laser desorption/ionization (LDI). The QIT-MSexperiments were performed in a Bruker HCT instrument (Fig. 2)equipped with an electrospray ionization (ESI) source.
Fig. 1 – FTICR mass spectrometer. Fig. 2 – QIT mass spectrometer.
Research group1 QEf | f-element Chemistry Group
