Diffraction-based technology for the monitoring of contraction dynamics in 3D and 2D tissue models.

We present a novel optical device developed for the monitoring of dynamic behavior in extended 3D-tissue models in various culture environments based on variations in their speckle patterns. The results presented point out the benefit of the technology in terms of detection, accuracy, sensitivity and a reasonable read-out speed as well as reproducibility for the measurements and monitoring of cardiac contractions. We show that the optical read-out technology is suitable for long time monitoring and for drug screening. The method is discussed and compared to other techniques, in particular calcium imaging. The device is flexible and easily adaptable to 2D and 3D-tissue model screenings using different culture environments. The technology can be parallelized for automated read-out of different multi-well-plate formats.

Reactivity of bridged pentelidene complexes with isonitriles: a new way to pentel-containing heterocycles.

The reaction of [Cp*E{W(CO)5}2] (E=P (1a), As (1b); Cp*=1,2,3,4,5-pentamethylcyclopentadienyl) with isonitriles RNC (R=tBu, cyclohexyl (Cy), nBu) depends on the steric demand of the substituent at the isonitrile as well as on the stoichiometry of the starting materials. With tBuNC only the Lewis acid/base adducts [Cp*E{W(CO)5}2ACHTUNGTRENUNG(CNtBu)] (E=P (2a), As (2b)) are formed. The use of Cy and n-butylisonitrile leads first to the formation of the Lewis acid/base adduct, but only at low temperatures. At ambient temperatures, a rearrangement occurs and bicycloACHTUNGTRENUNG[3.2.0]heptane derivatives of the type [{C(Me)CACHTUNGTRENUNG( CH2)C(Me)C(Me)C(Me)}C(NR)-E{W(CO)5}2] (E=P, As; R=Cy, nBu) (3a-Cy, 3b-Cy, 3a-nBu and 3b-nBu) are obtained. The use of a further equivalent of isonitrile results in products revealing two new structural motifs, the four-membered ring derivatives [CACHTUNGTRENUNG(Cp*)N(R)C(NR)E{W(CO)5}2] (4: E=P, As; R=Cy, nBu) and the bicyclic complexes [[{C(Me)CACHTUNGTRENUNG( CH2)C(Me)C(Me)C(Me)}C(NR)2-E{W(CO)5}2] (5: E=As; R=Cy). The reaction pathway depends on the substituent at the isonitrile. By treatment of 1a with two equivalents of CyNC only a 2H-1,3-azaphosphet complex 4a-Cy (E=P; R=Cy) is formed. Treatment of 1b with two equivalents of CyNC exclusively leads to the complex 5b-Cy (E=As; R=Cy). Treatment of 1a with two equivalents of nBuNC results in a mixture of complexes, the 2H-1,3-azaphosphet 4a-nBu (E=P; R=nBu) and the bicyclic complex 5a-nBu (E=P; R=nBu). For the arsenidene complex 1b a mixture of the 2H-1,3-azarsete complex 4b-nBu (E=As; R=nBu) and the bicyclic complex 5b-nBu (E=P, As; R=Cy, nBu) is obtained. Complex 4b-nBu is the first example of a 2H-1,3-azarsete complex. All products have been characterized by using mass spectrometry, NMR spectroscopy, and X-ray diffraction analysis.

Reactivity of bridged pentelidene complexes with isonitriles: a new way to pentel-containing heterocycles.

The reaction of [Cp*E{W(CO)5 }2 ] (E=P (1 a), As (1 b); Cp*=1,2,3,4,5-pentamethylcyclopentadienyl) with isonitriles RNC (R=tBu, cyclohexyl (Cy), nBu) depends on the steric demand of the substituent at the isonitrile as well as on the stoichiometry of the starting materials. With tBuNC only the Lewis acid/base adducts [Cp*E{W(CO)5 }2 (CNtBu)] (E=P (2 a), As (2 b)) are formed. The use of Cy and n-butylisonitrile leads first to the formation of the Lewis acid/base adduct, but only at low temperatures. At ambient temperatures, a rearrangement occurs and bicyclo[3.2.0]heptane derivatives of the type [{C(Me)C(CH2 )C(Me)C(Me)C(Me)}C(NR)- E{W(CO)5 }2 ] (E=P, As; R=Cy, nBu) (3 a-Cy, 3 b-Cy, 3 a-nBu and 3 b-nBu) are obtained. The use of a further equivalent of isonitrile results in products revealing two new structural motifs, the four-membered ring derivatives [C(Cp*)N(R)C(NR)E{W(CO)5 }2 ] (4: E=P, As; R=Cy, nBu) and the bicyclic complexes [[{C(Me)C- (CH2 )C(Me)C(Me)C(Me)}C(NR)2 - E{W(CO)5 }2 ] (5: E=As; R=Cy). The reaction pathway depends on the substituent at the isonitrile. By treatment of 1 a with two equivalents of CyNC only a 2H-1,3-azaphosphet complex 4 a-Cy (E=P; R=Cy) is formed. Treatment of 1 b with two equivalents of CyNC exclusively leads to the complex 5 b-Cy (E=As; R=Cy). Treatment of 1 a with two equivalents of nBuNC results in a mixture of complexes, the 2H-1,3-azaphosphet 4 a-nBu (E=P; R=nBu) and the bicyclic complex 5 a-nBu (E=P; R=nBu). For the arsenidene complex 1 b a mixture of the 2H-1,3-azarsete complex 4 b-nBu (E=As; R=nBu) and the bicyclic complex 5 b-nBu (E=P, As; R=Cy, nBu) is obtained. Complex 4 b-nBu is the first example of a 2H-1,3-azarsete complex. All products have been characterized by using mass spectrometry, NMR spectroscopy, and X-ray diffraction analysis.