Probing the Effects of Ligand Field and Coordination Geometry on Magnetic Anisotropy of Pentacoordinate Cobalt(II) Single-Ion Magnets

被引:66
作者
Mondal, Amit Kumar [1 ]
Goswami, Tamal [2 ]
Misra, Anirban [2 ]
Konar, Sanjit [1 ]
机构
[1] Indian Inst Sci Educ & Res Bhopal, Dept Chem, Bhopal Bypass Rd, Bhopal 462066, Madhya Pradesh, India
[2] Univ North Bengal, Dept Chem, Darjeeling 734013, W Bengal, India
关键词
INDUCED SLOW RELAXATION; MOLECULE-MAGNET; INTERMOLECULAR INTERACTIONS; SPIN-CROSSOVER; II COMPLEXES; BEHAVIOR; BLOCKING; DYNAMICS; IRON(II); TEMPERATURE;
D O I
10.1021/acs.inorgchem.7b00233
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
In this work, the effects of ligand field strength as well as the metal coordination geometry on magnetic anisotropy of pentacoordinated Co-II complexes have been investigated using a combined experimental and theoretical approach. For that, a strategic design and synthesis of three pentacoordinate Co-II complexes [Co(bbp)Cl-2]center dot(MeOH) (1), [Co(bbp)Br-2]center dot(MeOH) (2), and [Co(bbp)(NCS)(2)] (3) has been achieved by using the tridentate coordination environment of the ligand in conjunction with the accommodating terminal ligands (i.e., chloride, bromide, and thiocyanate). Detailed magnetic studies disclose the occurrence of slow magnetic relaxation behavior of Co-II centers with an easy-plane magnetic anisotropy. A quantitative estimation of ZFS parameters has been successfully performed by density functional theory (DFT) calculations. Both the sign and magnitude of ZFS parameters are prophesied well by this DFT method. The theoretical results also reveal that the alpha -> beta (SOMO-SOMO) excitation contributes almost entirely to the total ZFS values for all complexes. It is worth noting that the excitation pertaining to the most positive contribution to the ZFS parameter is the d(xy) -> d(x2-y2) excitation for complexes 1 and 2, whereas for complex 3 it is the d(z2) -> d(x2-y2) excitation.
引用
收藏
页码:6870 / 6878
页数:9
相关论文
共 113 条
[1]  
Abragam A., 1970, ELECT PARAMAGNETIC R
[2]   Shape maps and polyhedral interconversion paths in transition metal chemistry [J].
Alvarez, S ;
Alemany, P ;
Casanova, D ;
Cirera, J ;
Llunell, M ;
Avnir, D .
COORDINATION CHEMISTRY REVIEWS, 2005, 249 (17-18) :1693-1708
[3]  
[Anonymous], 1993, SHELXTL PROGRAM SOLU
[4]  
[Anonymous], 2010, ORCA 2.8.0
[5]   MOLCAS-a software for multiconfigurational quantum chemistry calculations [J].
Aquilante, Francesco ;
Pedersen, Thomas Bondo ;
Veryazov, Valera ;
Lindh, Roland .
WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE, 2013, 3 (02) :143-149
[6]   First-principle computation of zero-field splittings: Application to a high valent Fe(IV)-oxo model of nonheme iron proteins [J].
Aquino, F ;
Rodriguez, JH .
JOURNAL OF CHEMICAL PHYSICS, 2005, 123 (20)
[7]   Accurate Calculation of Zero-Field Splittings of (Bio)inorganic Complexes: Application to an {FeNO}7 (S=3/2) Compound [J].
Aquino, Fredy ;
Rodriguez, Jorge H. .
JOURNAL OF PHYSICAL CHEMISTRY A, 2009, 113 (32) :9150-9156
[8]   Room-Temperature Quantum Coherence and Rabi Oscillations in Vanadyl Phthalocyanine: Toward Multifunctional Molecular Spin Qubits [J].
Atzori, Matteo ;
Tesi, Lorenzo ;
Morra, Elena ;
Chiesa, Mario ;
Sorace, Lorenzo ;
Sessoli, Roberta .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2016, 138 (07) :2154-2157
[9]   Magnetic anisotropy in two- to eight-coordinated transition-metal complexes: Recent developments in molecular magnetism [J].
Bar, Arun Kumar ;
Pichon, Celine ;
Sutter, Jean-Pascal .
COORDINATION CHEMISTRY REVIEWS, 2016, 308 :346-380
[10]   Chemical tuning of the magnetic relaxation in dysprosium(III) mononuclear complexes [J].
Batchelor, Luke J. ;
Cimatti, Irene ;
Guillot, Regis ;
Tuna, Floriana ;
Wernsdorfer, Wolfgang ;
Ungur, Liviu ;
Chibotaru, Liviu F. ;
Campbell, Victoria E. ;
Mallaha, Talal .
DALTON TRANSACTIONS, 2014, 43 (32) :12146-12149