TY - JOUR

T1 - Theoretical study of Re(IV) and Ru(II) bis-isocyanide complexes and their reactivity in cycloaddition reactions with nitrones

AU - Novikov, Alexander S.

AU - Kuznetsov, Maxim L.

PY - 2012/1/15

Y1 - 2012/1/15

N2 - Bis-isocyanide complexes of Re(IV) and Ru(II) trans-/cis-[ReCl 4(CNMe) 2] and trans-/cis-[RuCl 2(PH 3) 2(CNMe) 2] and their cycloaddition reactions with nitrone CH 2N(Me)O were extensively studied by theoretical (DFT) methods. The reactivity of these complexes is interpreted in terms of both kinetic and thermodynamic factors as well as of orbital and charge arguments. The ligation of CNMe to Re(IV) significantly activates the isocyanide towards the cycloaddition (by 10.8 kcal/mol in CH 2Cl 2 solution), and such an activation effect is comparable with that provided by Pt(II) and Pd(II). In contrast, the coordination of CNMe to Ru(II) does not change significantly the reactivity of isocyanide and even makes the reactions more endoergonic. The mechanism of the reactions is concerted asynchronous. The calculations predict an inhibition of cycloaddition of the second nitrone molecule to the bis-isocyanide complexes and an easy decomposition of the derived N,N-substituted oxadiazolines via the NO bond rupture. The nature of the coordination bond in bis-and mono-isocyanide species and transition states was investigated in detail using the AIM, NBO and CDA analyses.

AB - Bis-isocyanide complexes of Re(IV) and Ru(II) trans-/cis-[ReCl 4(CNMe) 2] and trans-/cis-[RuCl 2(PH 3) 2(CNMe) 2] and their cycloaddition reactions with nitrone CH 2N(Me)O were extensively studied by theoretical (DFT) methods. The reactivity of these complexes is interpreted in terms of both kinetic and thermodynamic factors as well as of orbital and charge arguments. The ligation of CNMe to Re(IV) significantly activates the isocyanide towards the cycloaddition (by 10.8 kcal/mol in CH 2Cl 2 solution), and such an activation effect is comparable with that provided by Pt(II) and Pd(II). In contrast, the coordination of CNMe to Ru(II) does not change significantly the reactivity of isocyanide and even makes the reactions more endoergonic. The mechanism of the reactions is concerted asynchronous. The calculations predict an inhibition of cycloaddition of the second nitrone molecule to the bis-isocyanide complexes and an easy decomposition of the derived N,N-substituted oxadiazolines via the NO bond rupture. The nature of the coordination bond in bis-and mono-isocyanide species and transition states was investigated in detail using the AIM, NBO and CDA analyses.

KW - Cycloaddition

KW - DFT calculations

KW - Isocyanide complexes

KW - Reaction mechanism

KW - Rhenium

KW - Ruthenium

UR - http://www.scopus.com/inward/record.url?scp=84856231294&partnerID=8YFLogxK

U2 - 10.1016/j.ica.2011.08.016

DO - 10.1016/j.ica.2011.08.016

M3 - Article

AN - SCOPUS:84856231294

VL - 380

SP - 78

EP - 89

JO - Inorganica Chimica Acta

JF - Inorganica Chimica Acta

SN - 0020-1693

IS - 1

ER -