Yao-Cheng Shi

Syntheses and crystal structures of a tridentate enaminone and its copper complex

Reaction of ferrocenoylacetone [C5H5FeC5H4C(O)CH2C(O)CH3] and 2-aminoethanol yields a new ferrocene-containing ligand (H 2 L) that exists in the form of an enaminone formulated as [C5H5FeC5H4C(O)CH=C(NHCH2CH2OH)CH3]. Reaction of the enaminone H 2 L with copper acetate affords complex 1. X-ray crystallography of 1 reveals that it has a tetrameric structure composed of four CuL subunits linked by bridging alkoxide oxygen atoms in which the enaminone acts as a dianionic tridentate ligand and each of the four copper atoms is in a distorted square-pyramidal coordination environment.

NAIO4-CATALYZED ONE-POT SYNTHESIS OF DIHYDROPYRIMIDINONES AT ROOM TEMPERATURE UNDER SOLVENT-FREE CONDITIONS

Sodium periodate efficiently catalyzed the three-component Biginelli reaction of an aldehyde, α β-keto ester or β-keto ketone, and urea or thiourea at room temperature under solvent-free conditions and afforded the corresponding 3,4-dihydropyrimidine-2-(1H)-ones in excellent yields.

Novel One-Pot Procedure for the Synthesis of 1,2-Diketones

Abstract A simple and convenient one-pot procedure is reported for the synthesis of 1,2-diketones from corresponding benzoin-type condensation reaction of aromatic aldehydes in water with N,N-dialkylbenzimidazolium salt as condensation catalyst and ferric chloride as oxidizing reagent.

Syntheses, crystal structures, and electrochemistry of novel Fe2SN and FeSN carbonyl complexes with pendant bases

Reactions of Fe2(CO)9 with thioacylhydrazones ArCH=NNHCSPh in THF afford Fe2(CO)6(μ-κ2S:κ2N-PhC(S)=NNCHArCHArN(CHAr)N=CSPh) (1, Ar = C6H5; 3, Ar = 4-CH3C6H4) and Fe(CO)3(κ2S:N-PhC(=S)NHNCHArCHArN(CHAr)N=CSPh) (2, Ar = C6H5; 4, Ar = 4-CH3C6H4). They have been characterized by elemental analyses, IR, 1H NMR, and 13C NMR and structurally determined by X-ray crystallography. Electrochemical studies reveal that when using HOAc as a proton source, they exhibit high catalytic H2-production. Graphical abstract

Syntheses, molecular structures, and self-assemblies of SFe3, S2Fe3, S3Fe5, SeFe3, and Se2Fe3 clusters with chelating diaminocarbenes

The reactions of substituted thioureas and selenoureas with iron carbonyls have been systematically investigated, and five types of SFe3, S2Fe3, S3Fe5, SeFe3, and Se2Fe3 clusters with chelating diaminocarbenes have been synthesized and characterized by X-ray crystallography. The reactions of C3H5NHC(=S)NHAr with Fe3(CO)12 afford (μ3-S)Fe3(CO)7(μ-CO)(κ3C,C,C-C3H5NHCNHAr) (1, Ar = Ph; 2, Ar = 4-H2NC6H4). In contrast, the reactions of (2-C5H4N)NHC(=S)NHN=CHAr with Fe2(CO)9 form (μ3-S)2Fe3(CO)7(κ2N,C-(2-C5H4N)NHCNHN=CHAr) (3, Ar = Ph; 4, Ar = 4-CH3C6H4). Likewise, reactions of GNHC(=S)NHC(=O)Ph with Fe3(CO)12 provide (μ3-S)2Fe3(CO)7(κ2N,C-GNHCNHC(=O)Ph) (5, G = 2-C5H4N; 6, G = 2-C4H3N2) as well as Fe3(CO)8(μ-CO)2(κ2N,C-(2-C4H3N2)NHCNHC(=O)Ph). The reaction of (2-C5H4N)NHC(=S)NH2 with Fe3(CO)12 gives (μ3-S)2Fe3(CO)7(κ2N,C-(2-C5H4N)NHCNH2) (7). The reactions of GNHC(=S)NHPh with Fe3(CO)12 produce (μ3-S)2Fe3(CO)7(κ2N,C-GNHCNHPh) (8, G = 2-C5H4N; 9, G = 2-C4H3N2). Analogously, (2-C5H4N)NHC(=S)NH(2-CH3C6H4) offers (μ3-S)2Fe3(CO)7(κ2N,C-(2-C5H4N)NHCNH(2-CH3C6H4)) (10). However, (2-C5H4N)NHC(=S)NH(2-CH3OC6H4) generates (μ3-S)2(μ4-S)Fe5(CO)10(μ-CO)2(κ2N,C-(2-C5H4N)NHCNH(2-CH3OC6H4)) (11). Furthermore, the reactions of (2-C5H4N)NHC(=S)NHR with Fe3(CO)12 form (μ3-S)2(μ4-S)Fe5(CO)10(μ-CO)2(κ2N,C-(2-C5H4N)NHCNHR) (12, R = 2-H2NC6H4; 13, R = 4-H2NC6H4; 14, R = 2-C5H4N). Surprisingly, the reaction of (2-C5H4N)NHC(=S)NHC3H5 with Fe3(CO)12 leads to (μ3-S)2(μ4-S)Fe5(CO)10(μ-CO)2(κ2N,C-(2-C5H4N)NHCNHC3H5) (15). The reaction of C3H5NHC(=Se)NHPh with Fe3(CO)12 affords (μ3-Se)Fe3(CO)7(μ-CO)(κ3C,C,C-C3H5NHCNHPh) (16) as well as [(κ2N,C-PhNCNHC3H5)Fe2(CO)6(μ4-Se)Fe2(CO)6]2(μ4-Se). As with (2-C4H3N2)NHC(=S)NHPh, (2-C4H3N2)NHC(=Se)NHPh offers (μ3-Se)2Fe3(CO)7(κ2N,C-(2-C4H3N2)NHCNHPh) (17). Unlike (2-C5H4N)NHC(=S)NH(2-CH3OC6H4), (2-C5H4N)NHC(=Se)NH(2-CH3OC6H4) yields (μ3-Se)2Fe3(CO)7(κ2N,C-(2-C5H4N)NHCNH(2-CH3OC6H4)) (18). By virtue of N–HN, N–HO, and C–HO intermolecular hydrogen bonds along with other non-covalent interactions, these new organometallic clusters exhibit interesting supramolecular structures.

Syntheses, crystal structures, and electrochemical studies of diiron complexes from the reactions of [Et3NH][(μ-RS) Fe2(CO)6(μ-CO)] with isothiocyanates

Reactions of [Et3NH][(μ-MeO2CCH2S)Fe2(CO)6(μ-CO)] in situ generated from the mixture of MeO2CCH2SH, Et3N, and Fe3(CO)12 with 2-C5H4NNCS, 3-C5H4NNCS, and EtNCS in THF, form 1, (μ-MeO2CCH2S)Fe2(CO)5(μ-k2N,S:k2C-2-C5H4NNHCS), 2, (μ-MeO2CCH2S)Fe2(CO)6(μ-k2C,S-3-C5H4NNHCS), and 3, (μ-MeO2CCH2S)Fe2(CO)6(μ-k2C,S-EtNHCS). Reaction of [Et3NH][(μ-PhS)Fe2(CO)6(μ-CO)] in situ formed from the mixture of PhSH, Et3N, and Fe3(CO)12 with EtNCS affords 4, (μ-PhS)Fe2(CO)6(μ-k2C,S-EtNHCS). Reaction of [Et3NH][(μ-EtS)Fe2(CO)6(μ-CO)] in situ produced from the mixture of EtSH, Et3N, and Fe3(CO)12 with EtNCS offers 5, (μ-EtS)Fe2(CO)6(μ-k2C,S-EtNHCS). All new complexes have been fully characterized by EA, IR, 1H NMR, and 13C NMR and structurally determined by X-ray crystallography. Electrochemical studies on 2 and 5 confirm that 2 shows high H2-producing activity. Graphical abstract

μ4-Orthothio­carbonato-tetra­kis­[tri­carbonyl­iron(I)](2 Fe—Fe)

The fused bis-butterfly-shaped title compound, [Fe4(CS4)(CO)12], possesses an orthothiocarbonate (CS4 4−) ligand that acts as a bridge between two Fe2(CO)6 units. A short intramolecular S⋯S contact [2.6984 (8) and 2.6977 (8) Å] occurs in each S2Fe2(CO)6 fragment.

Syntheses and crystal structures of transition metal complexes of 1,1′-bisacetylacetoferrocene

Bimetallic complexes 3a–e of 1,1′-bisacetylacetoferrocene (2) were prepared by reactions of transition metal acetates M(OAc)2 (M = Co2+, Mn2+, Cu2+, Ni2+, Zn2+) with the 2 in refluxing methanol. The X-ray structures of the cobalt and manganese complexes were determined showing very similar centrosymmetric macrocyclic dimeric frameworks constituted by linkage of two Co2+ or Mn2+ ions and two 1,1′-diacetoacetylferrocene units with two additional methanols as bridges dividing this macrocyclic framework into two small cyclic subunits. The UV-Vis spectra and electronic properties were also studied.

Syntheses and crystal structures of Dimolybdenum complexes containing P2 and functionalized Cyclopentadienyl ligands

The dimolybdenum complex [(η5-RC5H4)2Mo2(CO)6] (1, R = CH3CO; II, R = CH3O2C) reacts with an equimolar amount of white phosphorus P4 to yield the corresponding dimolybdenum complex containing the P2 ligand [(η5-RC5H4)2Mo2(CO)4(μ,η2-P2)] (1, R = CH3CO; 2, R = CH3O2C) in moderate yield. The two new compounds have been characterized by elemental analyses, 1H NMR, 13C NMR, 31 P NMR and IR spectroscopies and their crystal structures have been determined by X-ray diffraction methods.

Two Fe3(μ3-S)2(CO)8 clusters with terminal N-heterocyclic carbenes

The title compounds with terminal N-heterocyclic carbenes, namely octacarbonyl(imidazolidinylidene-κC(2))di-μ3-sulfido-triiron(II)(2 Fe-Fe), [Fe3(C3H6N2)(μ3-S)2(CO)8], (I), and octacarbonyl(1-methylimidazo[1,5-a]pyridin-3-ylidene-κC(3))di-μ3-sulfido-triiron(II)(2 Fe-Fe), [Fe3(C8H8N2)(μ3-S)2(CO)8], (II), have been synthesized. Each compound contains two Fe-Fe bonds and two S atoms above and below a triiron triangle. One of the eight carbonyl ligands deviates significantly from linearity. In (I), dimers generated by an N-H···S hydrogen bond are linked into [001] double chains by a second N-H···S hydrogen bond. These chains are packed by a C-H···O hydrogen bond to yield [101] sheets. In (II), dimers generated by an N-H···S hydrogen bond are linked by C-H···O hydrogen bonds to form [111] double chains.