14N, 13C, and 119Sn solid-state NMR characterization of tin(II) carbodiimide Sn(NCN)

• We report the first magic-angle spinning (MAS) nuclear magnetic resonance (NMR) study on Sn(NCN). In this compound the spatially elongated (NCN)(2)- ion is assumed to develop two distinct forms: either cyanamide (NEC-N2-) or carbodiimide (N-=C=N-). Our N-14 MAS NMR results reveal that in Sn(NCN) the (NCN)(2-) groups exist exclusively in the form of symmetric carbodiimide ions with two equivalent nitrogen sites, which is in agreement with the X-ray diffraction data. The N-14 quadrupolar coupling constant vertical bar C-Q vertical bar approximate to 1.1 MHz for the N-=C=N- ion in Sn(NCN) is low when compared to those observed in molecular compounds that comprise cyano-type N C- moieties (vertical bar C-Q vertical bar > 3.5 MHz). This together with the information from N-14 and C-13 chemical shifts indicates that solid-state NMR is a powerful tool for providing atomic-level insights into anion species present in these compounds. The experimental NMR results are corroborated by high-level calculations with quantum chemistry methods.

Ämnesord

NATURVETENSKAP  -- Kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences (hsv//eng)

Nyckelord

DLPNO-CCSD

DSD-PBEP86

N-14 MAS NMR

SnCN2

Sn-119 MAS NMR

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