Alignment of Acentric Units in Infinite Chains: A “Lock and Key” Model

Polar chains built from acentric building units are of importance to investigate the mechanisms driving the polar alignment in the solid state. Our attempts to engineer polar chains in mixed metal oxide fluorides M′(2,2′-bpy)­(H₂O)₂MO_<i>x</i>F_6–<i>x</i> compounds [M′/M = Cu/Ti, Cu/V, Cu/Nb, Cu/Mo, Zn/Mo, and Zn/W] were successful using a combination of acentric anions [MO_<i>x</i>F_6–<i>x</i>]^2– and acentric cations [M′(2,2′-bpy)­(H₂O)₂]²⁺. A new general insight is also revealed: the alignment of polar units can be described with a “lock and key” model. The role of both the key (the acentric unit) and the lock (its environment) on the polarity in infinite chains is discussed

Preservation of Chirality and Polarity between Chiral and Polar Building Units in the Solid State

The new lamellar phases [Zn­(2,2′-bpy)₂(H₂O)₂]­(ZrF₆)·3H₂O (<b>I</b>) and [Ni­(2,2′-bpy)₃]­(MoO₂F₄)·5H₂O (<b>II</b>) (bpy = bipyridine), which are built from a chiral cation and respectively an inherently nonpolar and a polar anion, provide two contrasting structures with respect to chirality and polarity in the solid state. Each nonpolar layer of <b>I</b> contains enantiomers of both handednesses; conversely, each layer of <b>II</b> contains only a Δ or Λ enantiomer and polar anions oriented along the <i>b</i> or −<i>b</i> axes. A comparison with previously reported structures reveals which combinations and interactions between chiral and polar basic building units can preserve elements of polarity and chirality in the solid state

Alignment of Acentric Units in Infinite Chains: A “Lock and Key” Model

Polar chains built from acentric building units are of importance to investigate the mechanisms driving the polar alignment in the solid state. Our attempts to engineer polar chains in mixed metal oxide fluorides M′(2,2′-bpy)­(H2O)2MOxF6–x compounds [M′/M = Cu/Ti, Cu/V, Cu/Nb, Cu/Mo, Zn/Mo, and Zn/W] were successful using a combination of acentric anions [MOxF6–x]2– and acentric cations [M′(2,2′-bpy)­(H2O)2]2+. A new general insight is also revealed: the alignment of polar units can be described with a “lock and key” model. The role of both the key (the acentric unit) and the lock (its environment) on the polarity in infinite chains is discussed

Preservation of Chirality and Polarity between Chiral and Polar Building Units in the Solid State

The new lamellar phases [Zn­(2,2′-bpy)₂(H₂O)₂]­(ZrF₆)·3H₂O (<b>I</b>) and [Ni­(2,2′-bpy)₃]­(MoO₂F₄)·5H₂O (<b>II</b>) (bpy = bipyridine), which are built from a chiral cation and respectively an inherently nonpolar and a polar anion, provide two contrasting structures with respect to chirality and polarity in the solid state. Each nonpolar layer of <b>I</b> contains enantiomers of both handednesses; conversely, each layer of <b>II</b> contains only a Δ or Λ enantiomer and polar anions oriented along the <i>b</i> or −<i>b</i> axes. A comparison with previously reported structures reveals which combinations and interactions between chiral and polar basic building units can preserve elements of polarity and chirality in the solid state

Alignment of Acentric Units in Infinite Chains: A “Lock and Key” Model

Polar chains built from acentric building units are of importance to investigate the mechanisms driving the polar alignment in the solid state. Our attempts to engineer polar chains in mixed metal oxide fluorides M′(2,2′-bpy)­(H₂O)₂MO_<i>x</i>F_6–<i>x</i> compounds [M′/M = Cu/Ti, Cu/V, Cu/Nb, Cu/Mo, Zn/Mo, and Zn/W] were successful using a combination of acentric anions [MO_<i>x</i>F_6–<i>x</i>]^2– and acentric cations [M′(2,2′-bpy)­(H₂O)₂]²⁺. A new general insight is also revealed: the alignment of polar units can be described with a “lock and key” model. The role of both the key (the acentric unit) and the lock (its environment) on the polarity in infinite chains is discussed

Alignment of Acentric Units in Infinite Chains: A “Lock and Key” Model

Polar chains built from acentric building units are of importance to investigate the mechanisms driving the polar alignment in the solid state. Our attempts to engineer polar chains in mixed metal oxide fluorides M′(2,2′-bpy)­(H₂O)₂MO_<i>x</i>F_6–<i>x</i> compounds [M′/M = Cu/Ti, Cu/V, Cu/Nb, Cu/Mo, Zn/Mo, and Zn/W] were successful using a combination of acentric anions [MO_<i>x</i>F_6–<i>x</i>]^2– and acentric cations [M′(2,2′-bpy)­(H₂O)₂]²⁺. A new general insight is also revealed: the alignment of polar units can be described with a “lock and key” model. The role of both the key (the acentric unit) and the lock (its environment) on the polarity in infinite chains is discussed

Alignment of Acentric Units in Infinite Chains: A “Lock and Key” Model

Polar chains built from acentric building units are of importance to investigate the mechanisms driving the polar alignment in the solid state. Our attempts to engineer polar chains in mixed metal oxide fluorides M′(2,2′-bpy)­(H₂O)₂MO_<i>x</i>F_6–<i>x</i> compounds [M′/M = Cu/Ti, Cu/V, Cu/Nb, Cu/Mo, Zn/Mo, and Zn/W] were successful using a combination of acentric anions [MO_<i>x</i>F_6–<i>x</i>]^2– and acentric cations [M′(2,2′-bpy)­(H₂O)₂]²⁺. A new general insight is also revealed: the alignment of polar units can be described with a “lock and key” model. The role of both the key (the acentric unit) and the lock (its environment) on the polarity in infinite chains is discussed

Alignment of Acentric Units in Infinite Chains: A “Lock and Key” Model

Polar chains built from acentric building units are of importance to investigate the mechanisms driving the polar alignment in the solid state. Our attempts to engineer polar chains in mixed metal oxide fluorides M′(2,2′-bpy)­(H₂O)₂MO_<i>x</i>F_6–<i>x</i> compounds [M′/M = Cu/Ti, Cu/V, Cu/Nb, Cu/Mo, Zn/Mo, and Zn/W] were successful using a combination of acentric anions [MO_<i>x</i>F_6–<i>x</i>]^2– and acentric cations [M′(2,2′-bpy)­(H₂O)₂]²⁺. A new general insight is also revealed: the alignment of polar units can be described with a “lock and key” model. The role of both the key (the acentric unit) and the lock (its environment) on the polarity in infinite chains is discussed

Alignment of Acentric Units in Infinite Chains: A “Lock and Key” Model

Polar chains built from acentric building units are of importance to investigate the mechanisms driving the polar alignment in the solid state. Our attempts to engineer polar chains in mixed metal oxide fluorides M′(2,2′-bpy)­(H₂O)₂MO_<i>x</i>F_6–<i>x</i> compounds [M′/M = Cu/Ti, Cu/V, Cu/Nb, Cu/Mo, Zn/Mo, and Zn/W] were successful using a combination of acentric anions [MO_<i>x</i>F_6–<i>x</i>]^2– and acentric cations [M′(2,2′-bpy)­(H₂O)₂]²⁺. A new general insight is also revealed: the alignment of polar units can be described with a “lock and key” model. The role of both the key (the acentric unit) and the lock (its environment) on the polarity in infinite chains is discussed

Exciton Self-Trapping in Hybrid Lead Halides: Role of Halogen

Low-dimensional hybrid lead halides have recently been reported as efficient white light emitters. However, unlike lead halide 3D perovskites, most of the reported low-dimensional materials with broad-band emission crystallize in different structure types according to their halogen composition (i.e., Cl, Br, and I) for a selected organic molecule. Because of the absence of isostructural halide series, the role of chemistry in the self-trapping of the excitons at the origin of the broad-band emission remains unclear. Among the most efficient white phosphors, hybrid lead bromide (TDMP)­PbBr4 (TDMP = trans-2,5-di­methyl­piper­azinium) built of post-perovskite type chains exhibits a record photoluminescence quantum yield for hybrid lead halides. In this article, the two new isostructural (TDMP)­PbX4 chloride and iodide analogues could be synthesized and structurally characterized. A comparison of the optical properties of the lead halide series reveals a strong dependence of the nature of the halogen (Cl, Br, or I) on the trapping/detrapping of the excitons and the resulting emission intensities, wavelengths, and band broadness