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

From Racemic Units to Polar Materials

A new route is described that enables the design of polar materials using racemic basic building units (BBUs). Λ- and Δ-[Cu­(H2O)­(bpy)2]2+ complexes in noncentrosymmetric [Cu­(H2O)­(bpy)2]2[HfF6]2·3H2O and centrosymmetric [Cu­(H2O)­(bpy)2]­[BF4]2 reveal that racemic BBUs in the solid state can lead directly to noncentrosymmetry. The structure is polar if only mirror or glide planes relate the left- and right-handed enantiomers, whereas nonpolar, achiral structures result if rotoinversion relates the left- and right-handed enantiomers. This structural analysis also provides an alternative route in the design of polar materials that had always been engineered from polar BBUs