Hui-Zhen Zhu

Synthesis, crystal structure and magnetic properties of A[Ni(mnt)2] complexes [A = 1-(4-nitrobenzyl)quinolinium or 1-benzylpyridinium; mnt2− = maleonitriledithiolate]

Two new ion-pair complexes A[Ni(mnt)2], [A = 1-(4-nitrobenzyl)quinolinium (1), and 1-benzylpyridinium (2)] have been prepared and characterized. The crystal structure of (1) has been determined by X-ray diffraction analysis. In the solid state, anions and cations of (1) form completely segregated stacking columns, with the Ni···Ni distances alternating between 3.890(4) and 4.965(5) Å in the [Ni(mnt)2]− stacking column. The variable temperature magnetic susceptibilities of (1) and (2) have been measured over the 77–300 K range and the results reveal that (1) is diamagnetic and that (2) shows a weak antiferromagnetic spin exchange interaction between the metal ions. The e.p.r. spectra of (1) and (2) in MeCN at room temperature were similar, the g-values being almost identical.

Racemic titanium(IV) complexes of salicylideneamino acids

New racemic complexes of titanium with Schiff bases derived from condensation of salicylaldehyde with dl-alanine (H2Sal-dl-Ala) and dl-valine (H2Sal-dl-Val) have been prepared. The crystal structure of [(Sal-dl-Val)2Ti·CH2Cl2 bis(N-salicylidenevalinato)titanate(IV) CH2Cl2] has been solved by single-crystal X-ray diffraction methods; the crystal is a racemate consisting of a pair of enantiomers (Sal-d-Val)2Ti and (Sal-l-Val)2Ti. The Schiff-base ligand acts as a double negatively-charged tridentate ONO chelate, coordinated to the titanium atom. The geometry around titanium is a distorted octahedron. The i.r. and u.v.–vis. spectra of the complexes have been evaluated.

Synthesis, crystal structure, and properties of [Cu(LH)]2[M(mnt)2] [M = Ni or Cu; H2L = 3,3′-(1,3-propanediyldinitrilo)-bis(2-butanone oxime); mnt2− = maleonitriledithiolate] complexes containing bridging cyano groups

Interesting complexes containing a mnt2− bridge, based on the reaction of [M(mnt)2]2− [M = Ni or Cu] with [Cu(LH)]+, have been prepared and characterized by e.s.m.s., i.r and u.v–vis. spectroscopic techniques and by electrochemistry. The complexes show weak antiferromagnetic interactions between magnetic centers. The X-ray analysis of the molecular structure of [Cu(LH)]2[Ni(mnt)2] has been completed. It structurally features the CN group of mnt2− which can act as a bridging ligand between two transition metals.

Intramolecular photo-substitution in the inclusion compound of mono[6-deoxy-6-(2-aminoethyl thio-1,2-dicyane ethylenylthio)]-β-cyclodextrin with cyclopentadienyl manganese tricarbonyl in DMF solution

Abstract A novel host of β-cyclodextrin (β-CD) derivative, mono[6-deoxy-6-(2-aminoethyl thio-1,2-dicyane ethylenylthio)]-β-CD ( 3 ), and its inclusion compound 4 with cyclopentadienyl manganese tricarbonyl (CpMn I (CO) 3 ) have been prepared and characterized by spectroscopic methods. It is experimentally evident that the inclusion complexation stabilized the guest extremely when complex 4 was heated. Upon irradiation of inclusion compound 4 in DMF solution, an interesting intramolecular photo-substitution resulting in the formation of a self-stabilized compound mono[6-deoxy-6-(2-aminoethyl thio-1,2-dicyane ethylenylthio)]-β-CDMn II Cp(DMF) 2 ( 7 ) was observed. Based upon a double-recognition between the host and the organometallic guest, compound 7 became very stable in DMF solution.

The Inclusion Complex of Ferrocene with a Dithiolene Functionalized β-Cyclodextrin

A new βcyclodextrin derivative with the anion side-arm, mono[6-deoxy-6-(2-sodium thio-1,2-dicyane ethylenylthio)]-βcyclodextrin (6-mnt-βCD), and its inclusion complex with ferrocene (6-mnt-βCD/Fc), have been prepared and characterized by elemental analysis, IR spectroscopy, UV spectroscopy, mass spectrometry, 13C-NMR spectroscopy, thermogravimetry, and cyclic voltammetry (CV). Thermogravimetry analysis of the compound shows that the thermal stabilities of both the host and the guest in the inclusion complex have been greatly improved due to an additional interaction between the side-arm of the host and the guest. The interplay between the guest and the host with side-arm in the complex resulted in smaller positive potential shifts in CV compared to that in the inclusion complex βCD/Fc.

Intramolecular photo-substitution in the inclusion compound of mono[6-deoxy-6-(2-butenedinitrile-2,3-dimercapto sodium salt)]–β-cyclodextrin with cyclopentadienyl manganese tricarbonyl in DMF solution

A novel β-CD derivative, mono[6-deoxy-6-(2-butenedinitrile-2,3-dimercapto sodium salt)]–β-CD 1, and its inclusion compound 2 with CpMnI(CO)3 have been prepared and characterized by spectroscopic methods. The inclusion complexation significantly stabilized both the host and guest. Upon irradiation of inclusion compound 2 in DMF solution, an interesting intramolecular photo-substitution resulting in the formation of a self-stabilized compound mono[6-deoxy-6-(2-butenedinitrile-2,3-dimercapto sodium salt)]–β-CD–MnII(DMF)2Cp 5 was observed. Based upon a double-recognition between the host and the organometallic guest, compound 5 became very stable in DMF solution.

Preparation and electrochemistry of mixed nuclear complexes (OC)3 CrAreneCCo3(CO)9

SummaryFour new mixed nuclear complexes of general formula (OC)3CrAreneCCo3(CO)9, prepared by reacting (OC)3-CrAreneHgAreneCr(Co)3 with HCCo3(CO)9, were characterized by elemental analyses, i.r. and u.v. spectra. The complexes were electrochemically oxidized in acetone solution by an irreversible multi-electron process at ambient temperature, but displayed a chemically reversible one-electron process at −25°C. The resulting stable cation was easily attacked by nucleophiles such as PPh3. The results indicated that low-temperature cyclic voltammetry(LTCV) in acetone might be a useful way to study (arene)tricarbonylchromium complexes.