The heterotrinuclear complex [PtCu2(m-dppm)2(dmbpy)2(m-h1,h2 C CPhCH3-4)2] (ClO4)21.5CH2Cl2 1 (dmbpy = 4,4-dimethyl-2,2?bipyridine, dppm = bis(diphenylphosphino)meth- ane) has been prepared and characterized by X-ray...The heterotrinuclear complex [PtCu2(m-dppm)2(dmbpy)2(m-h1,h2 C CPhCH3-4)2] (ClO4)21.5CH2Cl2 1 (dmbpy = 4,4-dimethyl-2,2?bipyridine, dppm = bis(diphenylphosphino)meth- ane) has been prepared and characterized by X-ray crystallography. The complex crystallizes in the triclinic system, space group P with a = 12.9359(3), b = 14.3908(2), c = 15.2121(3) ? α = 107.370(1), β = 93.539(1), γ = 108.207(1), V = 2529.59(8) ?, Mr = 2015.96, Z = 1, Dc = 1.323 g/cm3, F(000) = 1019, m(MoKa) = 2.042 mm-1, the final R = 0.0604 and wR = 0.1529 for 8002 observed reflections with I > 2σ(I). The 4-methylphenylacetylides are bonded to the PtII and CuI centers in η1 (s) and η2 (p) coordination modes, respectively. The PtII atom is linked by one dppm bridge to adopt a square planar environment and CuI by one alkynyl ligand to assume a distorted tetrahedral geometry.展开更多
Combining in-depth neutron diffraction and systematic bulk studies,we discover that the√5×√5 Fe vacancy order,with its associated block antiferromagnetic order,is the ground state with varying occupancy ratios ...Combining in-depth neutron diffraction and systematic bulk studies,we discover that the√5×√5 Fe vacancy order,with its associated block antiferromagnetic order,is the ground state with varying occupancy ratios of the iron 16i and vacancy 4d sites across the phase-diagram of K_(x)Fe_(2)-ySe_(2).The orthorhombic order,with one of the four Fe sites vacant,appears only at intermediate temperatures as a competing phase.The material experiences an insulator to metal crossover when the√5×√5 order is highly developed.Superconductivity occurs in such a metallic phase.展开更多
基金NNSFC(No.20171044 and 20273074)NSF of Fujian Province (E0310029).
文摘The heterotrinuclear complex [PtCu2(m-dppm)2(dmbpy)2(m-h1,h2 C CPhCH3-4)2] (ClO4)21.5CH2Cl2 1 (dmbpy = 4,4-dimethyl-2,2?bipyridine, dppm = bis(diphenylphosphino)meth- ane) has been prepared and characterized by X-ray crystallography. The complex crystallizes in the triclinic system, space group P with a = 12.9359(3), b = 14.3908(2), c = 15.2121(3) ? α = 107.370(1), β = 93.539(1), γ = 108.207(1), V = 2529.59(8) ?, Mr = 2015.96, Z = 1, Dc = 1.323 g/cm3, F(000) = 1019, m(MoKa) = 2.042 mm-1, the final R = 0.0604 and wR = 0.1529 for 8002 observed reflections with I > 2σ(I). The 4-methylphenylacetylides are bonded to the PtII and CuI centers in η1 (s) and η2 (p) coordination modes, respectively. The PtII atom is linked by one dppm bridge to adopt a square planar environment and CuI by one alkynyl ligand to assume a distorted tetrahedral geometry.
基金Supported by the National Basic Research Program of China under Grant Nos 2012CB921700,2011CBA00112,2011CBA00103 and 2009CB929104National Natural Science Foundation of China under Grant Nos 11034012,11190024,10974175 and 10934005.
文摘Combining in-depth neutron diffraction and systematic bulk studies,we discover that the√5×√5 Fe vacancy order,with its associated block antiferromagnetic order,is the ground state with varying occupancy ratios of the iron 16i and vacancy 4d sites across the phase-diagram of K_(x)Fe_(2)-ySe_(2).The orthorhombic order,with one of the four Fe sites vacant,appears only at intermediate temperatures as a competing phase.The material experiences an insulator to metal crossover when the√5×√5 order is highly developed.Superconductivity occurs in such a metallic phase.
