Disodium[hydroxotetranitronitrosyl]ruthenate(II), a Photochromic
Substance with Long-lived Metastable States: Structure at 110 K,
Spectroscopic and Thermal Properties
Anna Puig-Molina*, Harald Mu
È
ller, Anne-Marie Le Que
Â
re
Â
, Gavin Vaughan, Heinz Graafsma, and A
Ê
ke Kvick
Grenoble/France, European Synchrotron Radiation Facility
Received July 13th, 2000.
Abstract. Disodium[hydroxotetranitronitrosyl]ruthenate(II)
is a photochromic compound excitable with blue-green light
which exhibits at least one unusually long-lived metastable
state at low temperature. At 298 K, the compound crystal-
lises in the space group C2/m. A reversible phase transition
occurs at 240 K upon cooling, as detected by Differential
Scanning Calorimetry and X-ray powder diffraction which
causes a lowering of the crystal symmetry to the space group
P2
1
/n. Synchrotron X-ray single crystal diffraction and FT-
IR spectroscopy data obtained on the ground and the ex-
cited states of the title compound low temperature phase are
presented.
Keywords: Ruthenium; Disodium[hydroxotetranitronitrosyl]-
ruthenate(II), Photochromism; Metastable states; Phase
transition; Crystal structure
Dinatrium[hydroxotetranitronitrosyl]ruthenat(II), eine photochrome Substanz
mit langlebigen metastabilen Zusta
È
nden: Struktur bei 110 K, spektroskopische
und thermische Eigenschaften
Inhaltsu
È
bersicht. Dinatrium[hydroxotetranitronitrosyl]ruthe-
nat(II) ist eine photochrome Substanz, die mit blau-gruÈnem
Licht angeregt werden kann und bei tiefen Temperaturen
wenigstens einen langlebigen, metastabilen Zustand hat. Die
Verbindung kristallisiert bei 298 K in der Raumgruppe
C2/m. Beim AbkuÈ hlen wurde mittels Differential Scanning
Calorimetry und RoÈntgenpulverbeugung ein reversibler Pha-
senuÈbergang bei 240 K beobachtet, der eine Verringerung
der Kristallsymmetrie zur Raumgruppe P2
1
/n zur Folge hat.
Die Ergebnisse von Einkristall-RoÈ ntgenbeugungsunter-
suchungen mit Synchrotronstrahlung und FT-IR Messungen
an der Tieftemperaturphase der Titelverbindung im Grund-
und angeregten Zustand werden vorgestellt.
Introduction
Several nitrosyl complexes of transition metals are
known to exhibit extraordinarily long-lived light-in-
duced metastable states (s > 10
7
sec) at low tempera-
ture. Such phenomena have been described for nitro-
syl complexes of iron, ruthenium and osmium with
different ligands and counterions and for NiCpNO
(Cp: g
5
-cyclopentadienyl) [1±8, 9]. Interestingly, the
observation of long-lived metastable states is not ne-
cessarily confined to a specific environment [6], while
the presence of the metal-NO group appears to be in-
dispensable for photo-excitation. In addition to the
particular interest of easily accessible metastable
states for fundamental physical chemistry, these
photochromic substances have been proposed as po-
tential candidates for optical storage elements, since
information can be repeatedly recorded, read and
erased employing light of specific wavelengths [10, 11].
Sodium nitroprusside, Na
2
[Fe(CN)
5
(NO)] ´ 2 H
2
O
(SNP), is by far the most extensively studied represen-
tative of this class of materials. This compound exhi-
bits two distinct light-induced metastable states MS1
and MS2 at temperatures below 200 K and 150 K, re-
spectively. The population of these states is strongly
dependent on light polarisation and wavelength [12].
A maximum population of about 50% of MS1 can be
reached in SNP single crystals with k = 457.9 nm light
and E perpendicular to the a±b plane [13]. The excited
states of SNP have been investigated by a plethora of
methods including X-ray and neutron diffraction,
XANES, IR, Raman, NMR, ESR, UV/vis and
MoÈûbauer spectroscopy as well as Differential Scan-
ning Calorimetry (DSC) [1, 2, 10, 12±24]. Notwith-
standing these considerable efforts, the origin of the
unusually long lifetimes and the exact nature of the
metastable states are not yet fully understood. Elec-
tronic excitation processes have been suggested as ori-
gin of the long-lived metastable states [10, 25, 26]. In
Z. Anorg. Allg. Chem. 2000, 626, 2379±2387 Ó WILEY-VCH Verlag GmbH, D-69451 Weinheim, 2000 0044±2313/00/6262379±2387 $ 17.50+.50/0 2379
* Dr. A. Puig-Molina,
ESRF,
BP 220,
F-38043 Grenoble/France
e-mail: puig@esrf.fr
下载后可阅读完整内容，剩余8页未读，立即下载
weixin_38692666
- 粉丝: 6
- 资源: 914
我的内容管理
展开
最新资源
- OptiX传输试题与SDH基础知识
- C++Builder函数详解与应用
- Linux shell (bash) 文件与字符串比较运算符详解
- Adam Gawne-Cain解读英文版WKT格式与常见投影标准
- dos命令详解：基础操作与网络测试必备
- Windows 蓝屏代码解析与处理指南
- PSoC CY8C24533在电动自行车控制器设计中的应用
- PHP整合FCKeditor网页编辑器教程
- Java Swing计算器源码示例：初学者入门教程
- Eclipse平台上的可视化开发：使用VEP与SWT
- 软件工程CASE工具实践指南
- AIX LVM详解：网络存储架构与管理
- 递归算法解析：文件系统、XML与树图
- 使用Struts2与MySQL构建Web登录验证教程
- PHP5 CLI模式：用PHP编写Shell脚本教程
- MyBatis与Spring完美整合：1.0.0-RC3详解
资源上传下载、课程学习等过程中有任何疑问或建议，欢迎提出宝贵意见哦~我们会及时处理！
点击此处反馈
