Navigation Links
Direct observation of carbon monoxide binding to metal-porphyrines
Date:1/10/2011

The mechanism for binding oxygen to metalloporphyrins is a vital process for oxygen-breathing organisms. Understanding how small gas molecules are chemically bound to the metal complex is also important in catalysis or the implementation of chemical sensors. When investigating these binding mechanisms, scientists use porphyrin rings with a central cobalt or iron atom. They coat a copper or silver support surface with these substances.

An important characteristic of porphyrins is their conformational flexibility. Recent research has shown that each specific geometric configuration of the metalloporphyrins has a distinct influence on their functionality. In line with the current state of research, the scientists expected only a single CO molecule to bind axially to the central metallic atom. However, detailed scanning tunnel microscopy experiments by Knud Seifert revealed that, in fact, two gas molecules dock between the central metallic atom and the two opposite nitrogen atoms. Decisive is the saddle shape of the porphyrin molecules, in which the gas molecules assume the position of the rider.

The significance of the saddle geometry became apparent in model calculations done by Marie-Laure Bocquet from the University of Lyon. Her analysis helped the researchers understand the novel binding mode in detail. She also showed that the shape of the molecular saddle remains practically unchanged, even after the two gas molecules bind to the porphyrin.

The porphyrins reacted very differently when the researchers replaced the carbon monoxide with stronger-binding nitrogen monoxide. As expected, this binds directly to the central atom, though only a single molecule fits in each porphyrin ring. This has a significant effect on the electronic structure of the carrier molecule, and the characteristic saddle becomes flattened. Thus, the porphyrin reacts very differently to different kinds of gas a result that is relevant for potential applications, such as sensors.

Dr. Willi Auwaerter, one of the authors, is thrilled: "What's new is that we actually saw, for the first time, the mechanism on a molecular level. We even can selectively move individual gas molecules from one porphyrin to another." The team aims to explain the physical and chemical processes on surfaces and in nanostructures. Once these fundamental questions are answered, they will take on new challenges: How big is the influence of the central atom? How does the binding change in planar conformations? How can such systems be utilized to implement catalyzers and sensors through controlled charge transfers?


'/>"/>

Contact: Dr. Andreas Battenberg
battenberg@zv.tum.de
49-892-891-0510
Technische Universitaet Muenchen
Source:Eurekalert  

Related biology news :

1. Directed self-assembly of vertical nanotubes for biosensors, logic, nano-biofuel cells
2. Elsevier announces the SciVerse ScienceDirect eBooks collection 2011 frontlist
3. UNC scientist receives NIH directors New Innovator Award
4. Tile drainage directly related to nitrate loss
5. LSUs WAVCIS director says oil remains below surface, will come ashore in pulses
6. UTHealth neuroscientist wins prominent NIH Directors Pioneer Award
7. Researchers demonstrate highly directional terahertz laser rays
8. Case Western Reserve geneticist receives prestigious NIH Directors Pioneer Award
9. A collaboration solves the herpes virus protein structure providing new drug therapy directions
10. Scientists find direct line from development to growth
11. New study first to directly measure body temperatures of extinct species
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Direct observation of carbon monoxide binding to metal-porphyrines
(Date:4/28/2016)... -- First quarter 2016:   , Revenues ... first quarter of 2015 The gross margin was 49% ... and the operating margin was 40% (-13) Earnings per ... from operations was SEK 249.9 M (21.2) , Outlook ... 7,000-8,500 M. The operating margin for 2016 is estimated ...
(Date:4/15/2016)... -- Research and Markets has announced the ...  report to their offering.  ,      ... gait biometrics market is expected to grow at ... Gait analysis generates multiple variables such ... compute factors that are not or cannot be ...
(Date:3/29/2016)... Florida , March 29, 2016 ... the "Company") LegacyXChange "LEGX" and SelectaDNA/CSI Protect are pleased ... in ink used in a variety of writing instruments, ... Buyers of originally created collectibles from athletes on LegacyXChange ... forensic analysis of the DNA. Bill ...
Breaking Biology News(10 mins):
(Date:6/24/2016)... Brooklyn, NY (PRWEB) , ... June 24, 2016 , ... ... 15mm, machines such as the Cary 5000 and the 6000i models are higher end ... height is the height of the spectrophotometer’s light beam from the bottom of the ...
(Date:6/23/2016)... , June 23, 2016 /PRNewswire/ - FACIT ... Ontario biotechnology company, Propellon Therapeutics ... development and commercialization of a portfolio of first-in-class ... Epigenetic targets such as WDR5 represent an exciting ... significantly in precision medicine for cancer patients. Substantial ...
(Date:6/23/2016)... June, 23, 2016  The Biodesign Challenge (BDC), a ... ways to harness living systems and biotechnology, announced its ... in New York City . ... students, showcased projects at MoMA,s Celeste Bartos Theater during ... , MoMA,s senior curator of architecture and design, and ...
(Date:6/23/2016)... 2016 Apellis Pharmaceuticals, Inc. today announced ... of its complement C3 inhibitor, APL-2. The trials ... dose studies designed to assess the safety, tolerability, ... in healthy adult volunteers. Forty subjects ... single dose (ranging from 45 to 1,440mg) or ...
Breaking Biology Technology: