Supramolecular Organic and Organometallic Chemistry Centre

Abstract
The goal of this proposal is to obtain new homo- and heteroleptic diorganochalcogenides which can behave as uni (E) or polidentate (N/E or O/E) ligands towards metal or organometallic centres. The main objectives are: (i) to design derivatives of type RR'E (E = Se,Te; R,R' = organic groups with donor atoms capable for intra- or intermolecular interactions) and their main group (Sn, Bi) and d (Pd, Pt, Au, Ag, Zn, Cd, Hg) metal complexes; (ii) to study their solution behavior and solid state structure, (iii) to assay their antitumor activity against commercial tumor cell lines, (iv) to investigate, the optical properties, (v) to find optimized combinations of organic groups/donor atoms/metals and synthesis strategies, based on experimental evidence and theoretical approach (DFT, QSAR), (vi) to investigate the relation structure-activity for selected classes of compounds and (vii) to identify the interaction mechanisms. The proposed organochalcogen compounds are potential tridentate systems, containing, besides Se or Te, other functionalities [chalcogenazolone, pyrazole (pz), phenylthiazole (Phtz), amino, imino, COOH, OH] and display hard/soft combinations of donor atoms. The chosen ligands and their metal complexes are very attractive both for fundamental research and as promising active agents for applications in biology or optoelectronics. The project is essentially based on an inter- and multidisciplinary approach and it combines research excellence and complementarity.

Rezumat
Scopul acestui proiect este de a obține noi diorganocalcogenuri homo- sau heteroleptice care se pot comporta ca liganzi uni (E) sau polidentați (N/E sau O/E) față de metale sau grupări organometalice. Principalele obiective sunt: (i) designul unor derivați RR'E (E = Se,Te; R,R' = grupări organice cu atomi donori capabili să coordineze intra- sau intermolecular) și complecși ai acestora cu metale din grupele principale (Sn, Bi) sau metale d (Pd, Pt, Au, Ag, Zn, Cd, Hg); (ii) studii structurale în soluție și în stare solidă, (iii) investigarea activității antitumorale asupra unor linii comerciale de celule canceroase, (iv) investigarea proprietăților optice, (v) găsirea a unor strategii de sinteză și a unor combinații optimizate grupare organică/atomi donori/metal pentru obținerea de specii cu activitate specifică ridicată, pe baza studiilor experimentale și teoretice (DFT, QSAR), (vi) investigarea relației structură-activitate și (vii) identificarea mecanismelor de interacțiune. Compușii calcogen-organici propuși sunt sisteme potențial polidentate, care conțin pe lângă Se sau Te și alte grupe funcționale [calcogenazolonă, pirazol (pz), feniltiazol (Phtz), amino, imino, COOH, OH] care prezintă combinații hard/soft de atomi donori. Liganzii aleși și complecșii metalici prezintă interes atât pentru cercetarea fundamentală, cât și pentru aplicații în biologie sau optoelectronică. Proiectul se bazează pe studii inter- și multidisciplinare.

Results

The implementation of the project during January 2025 – December 2025
The activities developed during the implementation of this project followed the objectives proposed in the approved application (contract PCE 51/2025), as depicted below:
Abstract
The activities developed during the implementation of this project followed the objectives proposed in the approved application (contract PCE 51/2025), as depicted below:
 (a) The synthesis of the necessary precursors (diorganodiselenides of type R₂Se₂)
 (b) The synthesis and structural characterization of new homo- and heteroleptic diorganochalcogen compounds of type RR'Se (R = R' = pzCH₂CH₂, (Z)-4′-{2-CH₃-(4H)-oxazol-5-one}CHC₆H₄, Me₂C(OH)CH₂; R ≠ R', R = 2-(Me₂NCH₂)C₆H₄, R = pzCH₂CH₂)
 (c) The synthesis of new organochalcogen compounds by the functionalization of pyridine with RSe or CH₂SeR (R = Me₂C(OH)CH₂) moieties;
 (d) The synthesis of new Sn(IV) complexes with homo- and heteroleptic RR'Se ligands;
 (e) The synthesis of new Sn(II) complexes with homo- and heteroleptic RR'Se ligands;
 (f) The synthesis of new complexes of group 11 metals;
 (g) Studies regarding the reactivity of diorganodiselenides towards Bi(I) moieties, e.g.. cyclo-([2-(Me₂NCH₂)C₆H₂]Bi)_n;
 (h) Structural investigation of the reported compounds in solution or in solid state;
 (i) Studies upon the antioxidant behaviour (GPx like) of diorganoselenides, based on the oxidation reaction of PhSH to PhSSPh;
All compounds were structurally investigated, in solution and in solid state, by spectroscopic methods (multinuclear NMR, ESI+ MS or APCI+ MS, UV-Vis, and IR spectroscopy). For the silver complexes the molar conductivities were determined, and their behaviour as 1:1 electrolytes was established.
Several compounds, for which single-crystals could be obtained, either diorganoselenides or metal complexes, the crystal and molecular structures were determined.
The catalitic activity of the compounds based on pyridine functionalized by organoselenium groups was investigated in the oxidation reaction of PhSH to PhSSPh. ¹H and ⁷⁷Se NMR spectroscopy were employed in order to assess the intermediary formation of the oxidized RR'Se=O species, as well as the formation of PhSSPh.

Published papers

1. Diorganotin(IV) Complexes of Organoselenolato Ligands with Pyrazole Moieties. Synthesis, Structure and Properties,
   M. Tamas, R. A. Butuza, M. Dan, A. Silvestru, Molecules, 2025, 30, 1648.
   DOI: 10.3390/molecules30071648, Impact Factor (2024) 4.6.
   
   
2. Homoleptic triorganotin(IV) organoselenolates of type R₃Sn(SeCH₂CH₂pz),
   M. Tamas, A. Pop, A. Silvestru, Rev. Roum. Chim., 2025, 70(5-6), 305-311.
   DOI: 10.33224/rrch.2025.70.5-6.07
   
   
3. Copper(II) complexes of diorganoselenium ligands containing a pyrazole functionality,
   R. A. Butuza, A. Pop, A. Silvestru, Rev. Roum. Chim., 2025, 70(7-8), 435-441.
   DOI: 10.33224/rrch.2025.70.7-8.07
   
   
4. Synthesis and structural characterization of silver(I) and gold(I) metal complexes containing a new homoleptic diorganoselenium(II) ligand,
   A.-D. Dănilă, C. Bohan, N. Chiorean, E. Gal, A. Pop, Rev. Roum. Chim., 2025, 70(11-12), in press.
   DOI:
   
   

Conferences

1. Insights to diorganoselenides based on functionalized pyridine. Synthesis, structure and reactivity,
   Anca Silvestru,
   oral presentation at WSeS 12, Jena, Germany, August, 2025.
   
   
2. Organoselenium compounds containing pyrene rings – Synthesis, structural characterization and investigation of the optical properties,
   Lucas Vicente, Alexandra Pop,
   oral presentation at WSeS 12, Jena, Germany, August, 2025.
   
   
3. Group 11 complexes of diorganoselenium ligands containing a 2,6-functionalized pyridine,
   Darius Dumitraș, Anca Silvestru,
   poster presentation at WSeS 12, Jena, Germany, August, 2025.
   
   
4. Silver(I) complexes with pyridine based diorganoselenium ligands. Synthesis and structural characterization,
   Cătălin Șalgău, Anca Silvestru,
   poster presentation at WSeS 12, Jena, Germany, August, 2025.
   
   
5. Oxidative addition of diselenides to bismuth(I): a route to organobismuth(III) bis(arylselenolate),
   Raffaele Fontana, Cristian Silvestru,
   oral presentation at WSeS 12, Jena, Germany, August, 2025.
   
   
6. Design, synthesis and investigation of organoselenium compounds containing oxazolones,
   Cosmina Bohan, Iris Angelușiu, Alexandra Pop,
   poster presentation at WSeS 12, Jena, Germany, August, 2025.
   
   
7. Organoselenium compounds as antioxidants and catalysts,
   Anca Silvestru,
   oral presentation at RomCat 14, Cluj-Napoca, Romania, July, 2025.
   
   
8. Heteroleptic diorganoselenides based on pyridine and pyrazole functionalities. Synthesis, structural characterization and coordination behaviour,
   Cătălin Șalgău,
   oral presentation at YRICCCE V, Cluj-Napoca, Romania, May, 2025.
   
   
9. Synthesis and Structural Characterization of New Pyrazole-Containing Homoleptic Diorganotellurium(II) Compounds,
   Eleonóra Kapronczai,
   poster presentation at YRICCCE V, Cluj-Napoca, Romania, May, 2025.
   
   
10. Structural aspects in organotin(IV) selenolates,
    Melinda Tamas,
    oral presentation at YRICCCE V, Cluj-Napoca, Romania, May, 2025.
    
    
11. Synthesis, structural characterization and reactivity of new pyridine based organoselenium compounds,
    Darius Dumitraș,
    oral presentation at YRICCCE V, Cluj-Napoca, Romania, May, 2025.
    
    

For information about unpublished results contact Prof. Dr. Anca Silvestru at anca.silvestru@ubbcluj.ro.-->