Supramolecular Organic and Organometallic Chemistry Centre

Abstract
Based on the significant importance of the organopnicogen (Sb, Bi) compounds in different fields, including fundamental aspects of their coordination chemistry, catalysis and organic synthesis, we propose a research project focused on the following topics: (i) studies on CO₂ fixation / activation by new organoantimony/bismuth species, including the screening as potential catalysts for the preparation of organic compounds using CO₂ as a C1-source, (ii) studies on organopnicogen species as catalysts for one-pot Mannich reactions and Lewis acid-catalyzed C−C bond-forming reactions, and (iii) triarylpnicogen(III) and -pnicogen(V) species as arylating agents for different organic substrates.
The studies are related to new neutral or ionic, mono or multinuclear organopnicogen compounds, e.g. [2-{E(R′)CH}C₆H₄MO]_n,
[2-{E(R′)CH}C₆H₄M(R)]⁺[A]^- (M = Sb, Bi; E = Me₂N, MeO; R′ = Me, i-Pr; R = Mes, 4-FC₆H₄, etc.) or organopnicogen(III) compounds with dendritic structure bearing azastibocine and azabismocine frameworks, which will be prepared either by new, original methods or by (adapted) literature procedures. Selected monoorganopnicogen(III) species will be used in reversible CO₂ fixation and C−H bond activation, while multinuclear compounds with dendritic structures will be tested in one-pot Mannich reaction, Lewis acid-catalyzed C−C bond-formation or transition metal catalyzed cross-coupling reactions. Ionic species will be also tested in CO₂ fixation in cyclic and/or polycarbonates and Mannich-type reactions.
The organic and organometallic compounds obtained within this project will be characterized in solution by multinuclear NMR, HRMS and IR spectroscopy. The molecular structure of the new compounds will be determined by single-crystal X-ray diffraction. DFT calculations will be used to predict or to explain the behavior of relevant compounds, including intermediates. The reaction products obtained in the catalysis tests will be investigated by GC-MS or HPLC-MS.

Results
Articles

• C–H Bond Activation Mediated by Main Group Inorganic and Organometallic Compounds of Main Group Metals.
  C. I. Raț, A. Soran, R. A. Varga, C. Silvestru in: P. J. Perez (Ed.) Advances in Organometallic Chemistry, Vol. 70, Elsevier: Cambridge, MA, United States, 2018, p. 233-311. DOI: 10.1016/bs.adomc.2018.07.003
  
  
• Hypercoordinated diorganoantimony(III) compounds of types [2-(Me₂NCH₂)C₆H₄]₂SbL and [PhCH₂N(CH₂C₆H₄)₂]SbL (L = Cl, ONO₂, OSO₂CF₃). Synthesis, structure and catalytic behaviour in the Henry reaction,
  R. Șuteu, C. I. Raț, C. Silvestru, A. Simion, N. Candu, V. I. Pârvulescu and A. Silvestru, Appl. Organomet. Chem., 2019, submitted. DOI:
  
  
• Chiral organoantimony(III) chalcogenides with the 2-(Et₂NCH₂)C₆H₄ ligand,
  A. Biró, I. Barteș, A. D. Rusu, H. J. Breunig, C.I. Raț and C. Silvestru, Dalton Trans., in preparation. DOI:
  
  

Conferences

• Main Group organometallics as building blocks for coordination polymers,
  C. Silvestru,
  at Journée scientifique en l'honneur du Prof. Marius ANDRUH à l'occasion de la remise des insignes de Docteur Honoris Causa de l'Université d’Angers, Angers (France), January 23, 2018 (invited lecture).
  
  
• Preparation of some bismuth(III) thiolates,
  G. Duneș,
  at The XVth International Conference „Students for Students”, Faculty of Chemistry and Chemical Engineering, Babeș-Bolyai University, Cluj-Napoca, April 17-21, 2018 (oral presentation).
  
  
• Organobismuth(V) transmetallation agents vs organometalloligands,
  A. Ben Kiran, T. Mocanu, A. Pollnitz, S. Shova, M. Andruh, C. Silvestru,
  at The IInd Young Researchers’ International Conference on Chemistry and Chemical Engineering (YRICCCE II), Budapest (Hungary), Mai 3-5, 2018 (oral presentation).
  
  
• Hypervalent compounds with N→Sb interactions,
  R. Șuteu, A. Silvestru,
  at The IInd Young Researchers’ International Conference on Chemistry and Chemical Engineering (YRICCCE II), Budapest (Hungary), Mai 3-5, 2018 (oral presentation).
  
  
• Main Group organometallics as building blocks for coordination polymers and supramolecular architectures,
  C. Silvestru,
  at A XXXVII-a Conferință Națională de Chimie, Căciulata, October 2-5, 2018 (invited plenary lecture).
  
  
• Organoantimony(V) compounds as metalloligands for coordination polymers,
  A. Ben Kiran, S. Shova, C. Silvestru,
  at A XXXVII-a Conferință Națională de Chimie, Căciulata, October 2-5, 2018 (poster).
  
  
• Catalytic effect of organobismuth(III) dications in Mannich reactions,
  A. János (Biró), C. I. Raț, C. Silvestru,
  at A XXXVII-a Conferință Națională de Chimie, Căciulata, October 2-5, 2018 (poster).
  
  
• Main Group organometallics as building blocks for coordination polymers and supramolecular architectures,
  C. Silvestru,
  at Department of Chemistry, Faculty of Science, University of Calgary, Calgary (Canada), October 11, 2018 (visiting speaker presentation).
  
  
• Sinteza și caracterizarea de noi compuși organometalici ai stibiului(III) și bismutului(III) de tipul [2-(GF*)C₆H₄]_nMX_3-n (M = Sb, Bi; n = 1-3; GF* = −CH=O, −CH=NCH₂C₆H₄N-2ʹ, −CH=NCH₂C₆H₄N-4ʹ),
  F.-A. Adăscăliței, C. Silvestru,
  at Conferința Școlilor Doctorale din Consorțiul Universitaria, Iași, October 31 - November 3, 2018 (oral presentation).
  
  
• New Hypercoordinated Organoantimony(III) Compounds,
  A. L. Corjuc, C. I. Raț,
  at 9th International Conference of the Chemical Societies of the South-East European Countries, Târgoviște, May 8 - 11, 2019 (poster).
  
  
• Hypercoordinated Diorganoantimony(III) Compounds as Catalysts for the Henry Reaction,
  R. Șuteu, N. Candu, V. Pârvulescu, A. Silvestru,
  at The 12th International Symposium of the Romanian Catalysis Society, București, June 5 - 7, 2019 (poster).
  
  
• Peculiar organopnicogen(III) (Sb, Bi) compounds and C–H activation,
  A. Sava, G. Duneș, A. Pöllnitz, C. Silvestru,
  at MA and Friends – coordination chemistry, Departamentul de Chimie Anorganica, Facultatea de Chimie, Universitatea București, București, October 31, 2019 (invited lecture).

Contributions to PhD Theses

For information about unpublished results contact Prof. Dr. Cristian Silvestru at cristian.silvestru (at) ubbcluj.ro.