Due to phase separation in the silicate melt, the synthesis of fluorosmectites ([Na0.5]inter[Mg2.5Li0.5]oct[Si4]tetO10F2) from the melt without mechanical mixing yields an inhomogeneous material. Because of the solid solution capability of the 2:1 layer silicate structure, the nonuniformity in chemical and mineral composition inevitably will lead to fluorosmectites that adopt a range of charge densities. This will be detrimental to many possible applications due to the large influence of layer charge on the properties of clay minerals. The problem can be circumvented by rotating the crucible during synthesis in a horizontal mounting, which will continuously force mixing of the melt mechanically. The product obtained is homogeneous at all length scales as judged by chemical analysis and its uniform intracrystalline reactivity. Noteworthy is its tendency to form regularly interstratified intercalates of monolayers and bilayers upon alkylammonium exchange and of rectorite type phases upon partial K+ exchange. We expect that the two dissimilar types of galleries, which are stacked in a regularly alternating pattern, can be selectively addressedleading to interesting intercalation materials.

Fluorosmectite, [M0.5]zwi[Mg2.5Li0.5]okt[Si4]tetO10F2 (M = Na, K, Rb, Cs), wurden über eine Schmelzsynthese in gasdicht verschweißten Mo‐Tiegeln dargestellt. Bei gleichbleibender, im Bereich der Smectite liegender, Schichtladung von x = 0.5 nimmt sowohl die Kristallitgröße als auch die Stapelordnung mit größer werdendem Zwischenschichtkation zu. Während beim mikrokristallinen Na‐Hectorit sowohl Rotations‐ (n120° und n60°) als auch Translationsfehlordnung (±0.145b) vorliegt, findet man für K‐Hectorit dagegen nur noch ±b/3 Translationsfehlordnung. Rb‐ und Cs‐Hectorit zeigen schließlich ein normales Bragg‐Beugungsmuster. Mit Cäsium als Zwischenschichtkation kann man vollkommen geordnete und sogar einkristalline Hectorite herstellen, die keinerlei diffuse Streuung mehr zeigen und eine Einkristallstrukturanalyse erlauben (monoklin, 1M—Polytyp, C2/m, a = 5.2401(10)Å, b = 9.0942(10) Å, c = 10.7971(10)Å, β = 99.21 (2)°, V = 507.90(12) Å3, Z = 2). Diese 3D geordneten Smectite besitzen immer noch eine ausreichende intrakristalline Reaktivität, die einen schnellen und vollständigen Austausch gegen Organokationen erlaubt.

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Minor modifications in molecular size and shape induced by variation of the central atom drastically alter the crystallization behaviour of the hexafluorophosphate salts of [M(bpy)3]2+. With M = Ru, racemic solutions crystallize as true racemates in the β‐type [P3¯c1, a = 10.6453(5), c = 16.2987(9) Å, Z = 2], while for M = Zn the racemic structure cannot be obtained, as spontaneous resolution {γ‐type [P31, a = 10.3873(5), c = 26.1309(16) Å, Z = 3]} is the only crystallization path observed. For [Ni(bpy)3](PF6)2, crystals of both structural types can be obtained concomitantly from the same crystallization batch. The γ‐phase is systematically twinned by merohedry. The dramatic and unpredictable change in the packing pattern of the very similar building blocks within this series arises from a delicate balance between the intermolecular forces. Distinct intermolecular interactions with different directionalities can be identified in the two structure types. Through careful analysis of the crystal and molecular structures, a trend with respect to molecular size and shape on going from [Ru(bpy)3](PF6)2 to [Zn(bpy)3](PF6)2 can be established. Even though one might speculate that increasing the size of the molecular cation should destabilize the β‐type structure relative to the γ‐type, no conclusive rationalization based solely on structural parameters can be given as regards why the relative order of the two local minima on the energy hypersurface should become inverted.