Photo-adjustability Of Magnetic Interactions By Photochromic Effects In Slice-like Transition Metal Coordination Complexes

Transition metal coordination complexes with bi-1,2-dithiolene as the ligands usually has planar and conjugated structure with electrons highly delocalization.In the crystal structure consisted of transition metal coordination complexes anions with bi-1,2-dithiolene and the finely counter cations,transition metal coordination complexes anions usually packing along one orientation.Sulphur atoms in the packing planar modules adjoin each other.Therefore,electrons in the planar and conjugated structure can be delivered by the adjoined sulphurs.As a result,complexes with bi-1,2-dithioleneusually has some properties such as optics,electricity and magnetic.Research for transition metal coordination anions with bi-1,2-dithiolene has been for decades,and large related research results have been achieved.In the crystal structure consisted of transition metal coordination anions with bi-1,2-dithiolene and the counter cations,the counter cations with different magnitude,configuration,or substituent groups usually can affect the style of packing.As we all know,the structure determine the property.So the choice of cations is a significant research direction.Take this law into attention,we synthesized two cations which have the characteristic of isomerization.Based on the cations’ isomerization,we design to introduce the cations into the low-dimensional magnet through covalent connection or non-covalent weak interaction.We are aimed at preparing the magnetic systems with photochromic effect of non-penetrated-layered type,and researching the interactions between photochromic effect and magnetization coupling.As to the transition metal coordination complexes with bi-1,2-dithiolene as the ligands,another aspect in consideration is to design the transition metal coordination complexes with bi-1,2-dithiolene to be the cation with a bridges such as-CH2CH2-.Similar to the common ways,we designed to cultivate crystals with this bridged transition metal coordination cations with bi-1,2-dithiolene and the usual transition metal coordination anions.Both structure of the cations and anions are planar,we predict that all the ions will pack one by one along one orientation.Both the cations and anions are magnetic and planar,the distance between the packing ions will be smaller,so the magnetic interaction may be very strong.Therefore,this design may give us a new thinking of the ion-pair magnetic complexes and exploit the field of functional material research.The main achievements are listed as follows:1.Photo-adjustability of magnetic interlayer interactions by photochromic effects in slice-like transition metal coordination complexesThe crystal structures and magnetic properties were investigated for two ion-pair complexes,which consisted of[Ni（mnt）2]-（mnt = 1,2-dithiolene）with[2-[[4-（dimethyIamino）phenyl]azo]-1-methyl-py]+ for complex 1 and[2-[[4-（dimethylamino）phenyl]azo]-1-benzyl-py]+ for complex 2.In complexes 1 and 2,cations and anions stacked into segregated columns.Magnetic susceptibility measurements in temperature range 2～300 K showed that complex 1 exhibited an antiferromagnetic coupling feature with θ=-0.0162 K,while 2 shows characteristic of spin-gap（△/κb = 38915.42 K）around 110 K.2.Research of the planar transition metal ion-pair complexThe charge transfer complexes with dithiolene ligands show unusual optical,electrical,magnetic and electrochemical properties,which lead to potential applications in the fields of semiconductor,superconductor,photoelectric conductor.We use Zn（dmit）2（Et4N+）2 as the structural unit to synthesize a planar ion-pair compound and characterize it by IR spectroscopy,¹H-and ¹³ C-NMR spectroscopy.