Treatment
of a digold(I) metalloligand, [AuI
2(dppe)(d-Hpen)2] (H2LAu; d-H2pen = d-penicillamine, dppe =
1,2-bis(diphenylphosphino)ethane), with a 1:1 mixture of Co(OAc)2 and Ni(OAc)2 under aerobic conditions resulted
in the formation of three types of hexanuclear complexes: [CoIII
2(LAu)2]2+,
[NiIICoIII(LAu)2]+, and [NiII
2(LAu)2]. The addition of NaNO3, M1NO3 (M1 = K, Rb, Cs), and M2(NO3)2 (M2 = Ca, Sr, Ba) to the reaction mixture led to co-crystallization
of [CoIII
2(LAu)2]2+ and [NiIICoIII(LAu)2]+ as a solid solution to form the charge-separation
(CS)-type ionic crystals 1
Na
, 1
M1
, and 1
M2
, respectively, while [NiII
2(LAu)2] independently crystallized as a single
species (2). In 1
Na
, [CoIII
2(LAu)2]2+ and [NiIICoIII(LAu)2]+ cations assemble in a 1:2 ratio to form a cationic
supramolecular octahedron accommodating 4 H3O+ ions, while 10 nitrate ions are packed in each hydrophilic tetrahedral
interstice of the crystal to form an anionic adamantane cluster. The
overall structures of 1
M1
and 1
M2
are very similar to that of 1
Na
, having a CS-type structure composed
of cationic supramolecular octahedra with a +12 charge and anionic
inorganic clusters with a −10 charge. However, 1
M1
contains M1 ions in place of
the H3O+ ions in 1
Na
, and furthermore, a novel rhombic dodecahedron cluster composed
of 14 nitrate ions, which encapsulates two M2 ions, is
formed in each hydrophilic tetrahedral interstice in 1
M2
.
The reaction of Na[Co III (D-ebp)] (D-H 4 ebp = N,N 0-ethylenebis[D-penicillamine]) with [(Au I Cl) 2 (dppe)] (dppe = 1,2-bis[diphenylphosphino]ethane) gave a cationic Au I 4 Co III 2 hexanuclear complex, [Co III 2 (L Au4)] 2+ ([1] 2+), where [L Au4 ] 4− is a cyclic tetragold(I) metalloligand with a 32-membered ring, [Au I 4 (dppe) 2 (D-ebp) 2 ] 4−. Complex [1] 2+ crystallized with NO 3 − to produce a charge-separation (CS)-type ionic solid of [1](NO 3) 2. In [1](NO 3) 2 , the complex cations are assembled to form cationic supramolecular hexamers of {[1] 2+ } 6 , which are closely packed in a face-centered cubic (fcc) lattice structure. The nitrate anions of [1](NO 3) 2 were accommodated in hydrophilic and hydrophobic tetrahedral interstices of the fcc structure to form tetrameric and hexameric nitrate clusters of {NO 3 − } 4 and {NO 3 − } 6 , respectively. An analogous CS-type ionic solid formulated as [Ni II Co III (L Au4)](NO 3) ([2](NO 3)) was obtained when a 1:1 mixture of Na[Co III (D-ebp)] and [Ni II (D-H 2 ebp)] was reacted with [(Au I Cl) 2 (dppe)], accompanied by the conversion of the diamagnetic, squareplanar [Ni II (D-H 2 ebp)] to the paramagnetic, octahedral [Ni II (D-ebp)] 2−. While the overall fcc structure in [2](NO 3) was similar to that of [1](NO 3) 2 , none of the nitrate anions were accommodated in any hydrophobic tetrahedral interstice, reflecting the difference in the complex charges between [1] 2+ and [2] + .
Mesoporous silica has attracted rapidly growing attention in catalysis. In this work, mesoporous silica was synthesized by using CTAB surfactant and then modified by AlCl 3 . Such material was used as support for Cu(II)--acetonitile complex and applied in transesterification of frying oil. The XRD pattern of the obtained silica confirms the availability of chracteristic peak on silica surface while its TEM exhibits the uniformity of nanochannel of the mesoporous silica. The particle size of silica support has become smaller after grafting process showed by SEM images. FT-IR spectra of the materials indicated that the Cu(II) grafted on the mesoporous silica was in the form of its acetonitrile complex. Supprisingly, the Cu loading the grafted catalyst was found to be very high. That was 21%, when the catalyst applied on transesterification of the examined frying oil the amount of total methyl ester yielded were of 65%.
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