Study of Electronic Effects on Normal vs. Abnormal Tetrazol-5-ylidenes at DFT

Document Type : Research Article


Department of Chemistry Tarbiat Modares University, Tehran, I.R. IRAN


We present electronic effects on stability (ΔES-T), nucleophilicity (N), global electrophilicity (ω), and band gaps (ΔEHOMO-LUMO) of 36 novel 1,4- and 1,3-tetrazole-5-ylidenes, 1 and 2, respectively. A union of three sets of "normal" 1W,W, 1D,D, and 1D,W are compared to another union of four sets of "abnormal" 2W,W, 2D,D, 2D,W and 2W,D NHCs, electron-withdrawing substituents (W) and electron-donating ones (D). Every 1 is more stable and shows a larger bandgap than its corresponding 2. In addition, philicities, N and ω, of every 2 appear larger than that of the corresponding 1 isomer. Carbenes with W groups increase electrophilicity while D ones increase nucleophilicity and in pull-push groups, W groups in carbene center increase electrophilicity. All our NHCs give doubly bonded head-to-head dimers except for 5 species.


Main Subjects

[1] Irikura K.K., Goddard W. A., Beauchamp J. L., Singlet-Triplet Gaps in Substituted Carbenes CXY (X, Y = H, F, C1, Br, I, SiH3), J. Am. Chem. Soc. 114:48-51(1992).
[2] Arduengo A. J., Harlow R. L., Kline M., A Stable Crystalline Carbene,  J. Am. Chem. Soc.113:363-365 (1991).
[3] Bourissou D., Guerret O., Gabbai F. P., Bertrand G., Stable Carbenes, Chem. Rev. 100: 39-91 (2000). 
[4] Arduengo A.J., Dias R.H.V., Harlow R.L., Kline M., Electronic Stabilization of Nucleophilic Carbenes, J. Am. Chem. Soc. 114: 5530-5534 (1992).
[5] Wanzlick H.W., Schönherr H.J., Chemie Nucleophiler Carbene, XVIII 1) Liebigs Ann. Chem., 731: 176 (1970).
[6] Heinemann C., Thiel W., Ab initio Study on the Stability of Diaminocarbenes, Chem. Phys. Lett., 217: 11 (1994).
[7] Rezaee N., Ahmadi A., Kassaee M.Z., Nucleophilicity of Normal and Abnormal N-heterocyclic Carbenes at DFT: Steric Effects on Tetrazole-5-ylidenes, RSC Adv. 6: 13224–13233 (2016).
[8] a) Kassaee M. Z., Musavi S. M., Ghambarian M., Bu-Azar F., Multiplicity vs. Stability in C2HP Carbenes and their Halogenated Analogues: an Ab initio and DFT Study, Journal of Molecular Structure: THEOCHEM, 726: 171–181 (2005).
b) Kassaee  M. Z., Ghambarian M., Musavi S. M., Halogen Switching of Azacarbenes C2NH Ground States at AB Initio and DFT Levels, Journal of Molecular Structure: THEOCHEM, 19(4): 377-388 (2008).
[9] Kassaee M. Z., Musavi S. M., Buazar F., An ab initio and DFT Comparative Study of Electronic Effects on Spin Multiplicities and Structures of X–C2N Carbenes, Journal of Molecular Structure: THEOCHEM, 728: 15–24 (2005).
[10] Kassaee M.Z., Ghambarian M., Musavi S.M., Shakib F.A., Momeni M. R., A Theoretical Investigation into Dimethylcarbene and its Diamino and Diphosphino Ana-Logs: Effects of Cyclization and Unsaturation on the Sta-Bility and Multiplicity, J. Phys. Org. Chem., 22: 919–924 (2009).
[11] Kassaee M. Z., Momeni M. R., Shakib F. A.,  Gham-barian M., Musavi S. M., Novel α-Spirocyclic (al-kyl)(amino)Carbenes at the Theoretical Crossroad of Flexibility and Rigidity, Struct Chem., 21:
593–598 (2010).
[12] Kassaee M. Z., Shakib F. A., Momeni. M. R.,  Gham-barian M., Musavi S. M., Carbenes with Reduced Het-eroatom Stabilization: A Computational Approach, J. Org. Chem., 75: 2539–2545 (2010).
[13] Kassaee M. Z., Ghambarian M., Shakib F. A., Momeni M. R., From Acyclic Dialkylcarbene to the Unsatu-Rated Cyclic Heteroatom Substituted Ones: A Survey of Stability,J. Phys. Org. Chem., 24: 351–359 (2011).
[14] Kassaee M. Z., Momeni M. R., Shakib F. A., Najafi Z., Zandi H., Effects of α-Cyclopropyl on Heterocyclic Carbenes Stability at DFT, J. Phys. Org. Chem., 24: 1022–1029 (2011).
 [15] Falivene L., Cavallo L., Theoretical NMR Spectroscopy of N-heterocyclic Carbenes and Their Metal Complexes, Coordination Chemistry Reviews, 344: 101–114 (2017).
 [16] Hammett  L. P., The Effect of Structure upon the Reactions of Organic Compounds. Benzene Derivatives, J. Am. Chem. Soc., 59(1): 96–103 (1937).
[17] Pulukkody R., Kyran S. ., Drummond M.J., Hsieh C.H.,  Darensbourg D.J., Darensbourg M.Y., Hammett Correlations as Test of Mechanism of CO- Induced Di-sulfide Elimination from Dinitrosyl Iron ComplexesChem. Sci., 5: 3795 (2014).
[18] Carey F. A., Sundberg R. J., “Advanced Organic chemistry”, Springer Science+Business Media, LLC, 233 Spring Street, New York, A, Chapter 3, pp 336-342 (2007).
[19] Kassaee M. Z., Azarnia J., Arshadi S., 1,2,4,6-Cycloheptatetraenes Racemizations: Substituent Effects via AB Initio, Journal of Molecular Structure: THEOCHEM, 686: 115–122 (2004).
[22] Zhao Y., Truhlar D.G., Density Functionals with Broad Applicability in Chemistry, Acc. Chem. Res., 41(2): 157–167 (2008).
[23] Domingo L. R., Chamorro E., Perez P. J., Understand-ing the Reactivity of Captodative Ethylenes in Polar Cycloaddition Reactions. A Theoretical Study, J. Org. Chem. 73: 4615–4624 (2008).
[24] Parr R.G., Szentpaly L., Liu S., Electrophilicity IndexJ. Am. Chem. Soc. 121: 1922–1924 (1999).
[25] Parr R. G., Pearson R. G., Absolute Hardness: Compan-ion Parameter to Absolute ElectronegativityJ. Am. Chem. Soc. 105: 7512–7516 (1983).
[26] Dıez-Gonzalez S., Nolan S. P., Stereoelectronic Parameters Associated with N-Heterocyclic Carbene (NHC) Ligands: A Quest for Understanding, Coordination Chemistry Reviews, 251: 874–883 (2007).
[28] Schleyer P.v. R., Maerker C., Dransfeld A., Jiao H., Eikema Hommes N.J.R.V., Nucleus-Independent Chemical Shifts: A Simple and Efficient Aromaticity Probe. J. Am. Chem. Soc., 118: 6317-6318 (1996).
[29] Jacobsen H., Correa A., Poater A., Costabile C., Cavallo. L., Understanding the M(NHC) (NHC = N-heterocyclic carbene) Bond, Coordination Chemistry Reviews, 253: 687–703 (2009) 
[30] Frison G., Huynh H. V.,  Bernhammer J. C., Electronic Structure Trends in N-Heterocyclic Carbenes (NHCs) with Varying Number of Nitrogen Atoms and NHC Transition Metal Bond Properties, Chem.–Eur. J., 19: 12892–12907 (2013).
[31] Hoffmann R., Gleiter R., Mallory F. B., Non-Least-Motion Potential Surfaces. Dimerization of Methyl-Enes and Nitroso Compounds, J. Am. Chem. Soc. 92: 1460–1466 (1970).
[32] Alder R. W., Blake M. E., Chaker L., Harvey J. N.,  Paolini F., Schutz, When and How Do Diaminocarbenes Dimerize? J.  Angew. Chem., Int. Ed., 43: 5896–5911 (2004).
[33] Poater A., Ragone F., Giudice S., Costabile C., Dorta R., Nolan S.P., Cavallo L., Thermodynamics of N-Heterocyclic Carbene Dimerization: The Balance of Sterics and Electronics, Organometallics, 27: 12- (2008).
[34] Frémont P., Marion N., Nolan S.P., Carbenes: Synthesis, Properties, and Organometallic Chemistry, Coordination Chemistry Reviews, 253: 862–892 (2009).
[35] Carter A. E., Goddard III W. A., Relation between Singlet-Triplet Gaps and Bond Energies, J. Phys. Chem. 90: 998–1001 (1986).
 [36] Trinquier G., Malrieu J. P., Nonclassical Distortions at Multiple Bonds, J. Am. Chem. Soc. 109: 5303–5315 (1987).
[37] Malrieu J.P., Trinquier G., Trans Bending at Double Bonds. Occurrence and Extent, J. Am. Chem. Soc., 111: 5916–5921 (1989).
[38] Liong C., Allen L. C., Group IV Double Bonds: Shape Deformation and Substituent Effects, J. Am. Chem. Soc. 112: 1039– 1041 (1990).
[39] Karni M., Apeloig Y., Substituent Effects on the Ge-ometries and Energies of the Si==Si Double Bond, J. Am. Chem. Soc., 112: 8589– 8590 (1990).
[40] Naderi F., Momeni M. R., Shakib F. A., A Density Functional Theory Study on the Stability and Ligand Properties of the Different Substituted Phenyl Carbenes, International Journal of Physical Sciences. 7: 2439-2444 (2012).
[41] Kassaee M. Z., Shakib F. A., Momeni M. R., Ghambarian M., Musavi S. M., A DFT Study on Pyridine-Derived N-Heterocyclic Carbenes, Tetrahedron, 65: 10093–10098 (2009).
[42] Sulzbach H. M., Bolton E., Lenoir D., Schleyer P. v. R., Schaefer H. F., Tetra-tert-butylethylene: An Elusive Molecule with a Highly Twisted Double Bond. Can It Be Made by Carbene Dimerization? J. Am. Chem. Soc. 118: 9908–9914 (1996).