Bridging couplings

Baldwin, M. J., P. K. Ross, J. E. Pate, Z. Tyeklar, K. D. Karlin, and E. I. Solomon. 1991. Spectroscopic and Theoretical Studies of an End-On Peroxide-Bridged Coupled Binuclear Cooper(II) Model Complex of Relevance to Active Sites in Hemocyanin and Tyrosinase. J. Am. Chem. Soc. 113, 8671. 

While this material has not been isolated, it is stable in ether solution. It boron-11 nmr spectrum consists of a singlet and doublet in the area ratio of 1 1 which is consistent with the proposed structure in general, bridge coupling is not observed for singly hydrogen-bridged structures. 

As a consequence, using the Bosons description and performing the rotating wave approximation lead us to write the effective Hamiltonians (102) and (103) describing the H-bond bridge coupled to the thermal bath as follows ... 

Figure 32. Matrix elements describing the coupling of a p (or n) orbital of the chromophore to an all-tran.s alkane bridge. The dominant chromophore-bridge coupling is represented by T.

Figure 1-6. Structural model of tmRu-Fgbp-Im bound in the active site of P450can,- The perfluorobiphenyl bridge couples Rm (L2)If to the heme, facilitating direct photoreduction (-AG° 0.45 eV) with a time constant of 36 ns. Adapted from ref. 91.

The reference arm bridge coupled to a microwave resonant structure operating in reflection has become the standard microwave geometry for ESR spectroscopy... 

This detector is used with ion chromatography only. The conductivity in the flow cell is measured by a Wheatstone bridge coupling, with pulsed techniques to avoid formation of electrical double layers at the electrodes. 

In the AC experiments the equivalent circuit of parallel resistor and capacitor Cj for the silver chloride-solution system is measured as a function of frequency, applied AC voltage, and using a Wayne-Kerr Universal Bridge coupled with a General Radio oscillator 1203-B and tuned amplifier null detector 1232-A The frequency was varied from 50 to 10 cps and voltage from 0.025 to 20 V. No voltage dependence was observed up to 0.8 V and the data shown later were taken at 50 and 1592 cps and at 0.3 V. 

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