Antifreeze Proteins (AFPs) inhibit the growth of an ice crystal by binding to it. The detailed binding mechanism is, however, still not fully understood. We investigated three AFPs using Molecular Dynamics simulations in combination with Grid Inhomogeneous Solvation Theory, exploring their hydration thermodynamics. The observed enthalpic and entropic differences between the ice-binding sites and the inactive surface reveal key properties essential for proteins in order to bind ice: While entropic contributions are similar for all sites, the enthalpic gain for all ice-binding sites is lower than for the rest of the protein surface. In contrast to most of the recently published studies, our analyses show that enthalpic interactions are as important as an ice-like pre-ordering. Based on these observations, we propose a new, thermodynamically more refined mechanism of the ice recognition process showing that the appropriate balance between entropy and enthalpy facilitates ice-binding of proteins. Especially, high enthalpic interactions between the protein surface and water can hinder the ice-binding activity.

An in situ generated dinuclear palladium hydride complex bearing cis,trans,cis-1,2,3,4-tetrakis(diphenylphosphanyl)cyclobutane catalyzed the hydromethoxycarbonylation of terminal alkynes, giving the corresponding branched α,β-unsaturated ester (A) with high regioselectivity.

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The bis(bidentate) phosphane cis,trans,cis-1,2,3,4-tetrakis-(diphenylphosphanyl)cyclobutane (dppcb) has been used for the synthesis of supramolecular complexes, so-called dyads and triads. Depending on the monometallic precursor compound [Ru(bpy) 2 (dppcb)](PF 6 ) 2 or [Ru(bpy) 2 (cis-dppcbO 2 )]-(PF 6 ) 2 [bpy = 2,2Ј-bipyridine, cis-dppcbO 2 = cis,trans,cis-1,2bis(diphenylphosphanoyl)-3,4-bis(diphenylphosphanyl)cyclobutane], [Ru(bpy) 2 (dppcb)NiBr 2 ](PF 6 ) 2 (1) or ΔΛ/ΛΔ-[{Ru(bpy) 2 (cis-dppcbO 2 )} 2 NiBr](PF 6 ) 5 (2) is exclusively formed in good yield by reaction with [NiBr 2 (DME)] (DME = dimethoxyethane). The versatile coordination behaviour of dppcb compared with that of cis-dppcbO 2 is confirmed by cis,trans,cis-2,3-bis(diphenylphosphanoyl)-1,4-bis(diphenylphosphanyl)cyclobutane (2,3-trans-dppcbO 2 , 4). Although two dppcb ligands coordinated simultaneously to a Pd II centre cannot produce a square-planar PdP 4 core, the reaction of two equivalents of 4 with [Pd(CH 3 CN) 4 ](BF 4 ) 2 exclusively leads to meso-(MMMP/MPPP)-[Pd(2,3-trans-dppcbO 2 -[a] 5122 trans-dppcbO 2 , 4) [11] in isolated form with palladium(II) was also investigated (Scheme 2). Usually, it is not possible to combine two dppcb ligands with one palladium(II) centre to generate a square-planar PdP 4 core. [12] However, two equivalents of 4 and one equivalent of [Pd(CH 3 CN) 4 ]-(BF 4 ) 2 exclusively produce meso-(MMMP/MPPP)-[Pd(2,3trans-dppcbO 2 -P,PЈ) 2 ](BF 4 ) 2 (3), which has this square-Eur. J. Inorg. Chem. 2013, 5121-5132

The indium oxide-borate In 4 O 2 B 2 O 7 was synthesized under high-pressure/high-temperature conditions at 12.5 GPa/1420 K using a Walker-type multianvil apparatus. Single-crystal X-ray structure elucidation showed edge-sharing OIn 4 tetrahedra and B 2 O 7 units building * Univ.-Prof. Dr. H. Huppertz 2103 up the oxide-borate. It crystallizes with Z = 8 in the monoclinic space group P2 1 /n (no. 14) with a = 1016.54(3), b = 964.55(3), c = 1382.66(4) pm, and β = 109.7(1)°. The compound was also characterized by powder X-ray diffraction and vibrational spectroscopy.