Abstract
Mercury cyanide complexes of alkyldiamines (1-6), [Hg(L)(CN)
2
] (where L = en (1,2-diaminoethane), pn (1,3-diaminopropane), N-Me-en, N, N′-Me
2
-en, N, N′-Et
2
-en, and N, N′-ipr
2
-en), have been synthesized and characterized by elemental analysis, IR,
13
C, and
15
N solution NMR in DMSO-d
6
, as well as
13
C,
15
N, and
199
Hg solid-state NMR spectroscopy. Complexes 1 and 2 have been studied computationally, built and optimized by GAUSSIAN03 using DFT at B3LYP level with LanL2DZ basis set. Binding modes of en and bn (where bn = 1,4-diaminobutane) toward Hg(CN)
2
are completely different. Complexes with en and pn show chelating binding to Hg(II), while bn behaves as a bridging ligand to form a polymeric structure, [Hg(CN)
2
-bn]
∞
[B.A. Al-Maythalony, M. Fettouhi, M.I.M. Wazeer, A.A. Isab. Inorg. Chem. Commun., 12, 540 (2009).]. The solution
13
C NMR of the complexes demonstrates a slight shift of the −C≡N (0.9 to 2 ppm) and −C-NH
2
(0.25 to 6 ppm) carbon resonances, while the other resonances are relatively unaffected.
15
N labeling studies have shown involvement of alkyldiamine ligands in coordination to the metal. The principal components of the
13
C,
15
N, and
199
Hg shielding tensors have been determined from solid-state NMR data. Antimicrobial activity studies show that the complexes exhibit higher antibacterial activities toward various microorganisms than Hg(CN)
2
.