Control of the Speed of a Light-Induced Spin Transition through Mesoscale Core-Shell Architecture.

The rate of the light-induced spin transition in a coordination polymer network solid dramatically increases when included as the core in mesoscale core-shell particles. A series of photomagnetic coordination polymer core-shell heterostructures, based on the light-switchable Rb Co [Fe(CN)] · mHO (RbCoFe-PBA) as core with the isostructural K Ni [Cr(CN)] · nHO (KNiCr-PBA) as shell, are studied using temperature-dependent powder X-ray diffraction and SQUID magnetometry. The core RbCoFe-PBA exhibits a charge transfer-induced spin transition (CTIST), which can be thermally and optically induced.

Crystal structure of aqua--bis-(dimethyl sulfoxide-κ)(pyridine-2,6-di-carboxyl-ato-κ,,)nickel(II).

In the title complex, [Ni(CHNO)(CHOS)(HO)], the Ni cation is situated on a twofold rotation axis and exhibits a distorted octa-hedral NO coordination environment defined by a tridentate pyridine-2,6-di-carb-oxy-lic acid dianion (dpa), two dimethyl sulfoxide (DMSO) mol-ecules, and a water mol-ecule. In the crystal, the complex mol-ecules are linked by O-H⋯O and C-H⋯O hydrogen bonds into a three-dimensional network whereby DMSO mol-ecules from neighboring complexes overlap to form layers parallel to (001), alternating with layers of Ni-dpa moieties. The title complex is isotypic with its cobalt(II) analogue.

Synergistic photomagnetic effects in coordination polymer heterostructure particles of Hofmann-like Fe(4-phenylpyridine)[Ni(CN)]·0.5HO and KNi[Cr(CN)]·nHO.

New nanometer scale heterostructure particles of the two-dimensional Hofmann-like Fe(ii) spin-crossover network, Fe(phpy)[Ni(CN)]·0.5HO {phpy = 4-phenylpyridine}, and the Prussian blue analogue KNi[Cr(CN)]·nHO (NiCr-PBA) have been developed, exhibiting synergistic photomagnetic effects, whereby the LIESST (light-induced electron spin-state trapping) effect in the Hofmann-like material induces a magnetization change in the NiCr-PBA. A variety of microscopic and spectroscopic techniques demonstrate the heterogeneous growth of the NiCr-PBA on the Hofmann seed particles and show the Hofmann compound retains its thermal and photoinduced spin transition properties in the heterostructure.

Crystal structure of catena-poly[[(dimethyl sulfoxide-κO)(pyridine-2,6-di-carboxyl-ato-κ(3) O,N,O')nickel(II)]-μ-pyrazine-κ(2) N:N'].

The title coordination polymer, [Ni(C7H3NO4)(C4H4N2)(C2H6OS)] n , consists of [010] chains composed of Ni(II) ions linked by bis-monodentate-bridging pyrazine mol-ecules. Each of the two crystallographically distinct Ni(II) ions is located on a mirror plane and is additionally coordinated by a dimethyl sulfoxide (DMSO) ligand through the oxygen atom and by a tridentate 2,6-pyridine-di-carb-oxy-lic acid dianion through one of each of the carboxyl-ate oxygen atoms and the pyridine nitro-gen atom, leading to a distorted octa-hedral coordination environment. The title structure exhibits an inter-esting complementarity between coordinative bonding and π-π stacking where the Ni-Ni distance of 7.

Crystal structure of catena-poly[[[trans-bis(aceto-nitrile-κN)diaquacobalt(II)]-μ-pyrazine-κ(2) N:N'] dinitrate].

The central structural motif of the title coordination polymer, [Co(NO3)2(C4H4N2)(CH3CN)2(H2O)2] n , is a chain composed of Co(II) ions linked by bis-monodentate bridging pyrazine ligands through their N atoms. The Co(II) ion is located on an inversion center and is additionally coordinated by two O atoms of water mol-ecules and two N atoms of aceto-nitrile mol-ecules. The resultant N4O2 coordination sphere is distorted octa-hedral.