Martin D. Rudd

N-Methylbenzothiazole-2(3H)-selone, C8H7NSSe

The crystal structure of N-methyl-1,3-benzothiazole-2(3H)-selone (mbts) has been studied in order to estimate the changes in the molecular geometry of the mbts ligand upon coordination. Hypervalent complexes of mbts with Te II and I I have been studied by us previously. A significant elongation of the Se=C bond [from 1.817 (7) in mbts to 1.85-1.88 A in the complexes] was found, but there were no significant changes in the other geometric parameters of the ligand. The only other bond-length decrease of note was for SeC-NMe [from 1.35 (1) in mbts to 1.32-1.34 A in the complexes]. Thus, only the amino group takes part in electron redistribution upon coordination.

TAUTOMERIC CONVERSION OF A THIOUREA LIGAND UPON FORMATION OF A HYPERVALENT TELLURIUM (II) COMPLEX. SYNTHESIS, AND X-RAY STRUCTURAL STUDIES OF N-PHENYL-N′-(1,3-THIAZOL-2-YL)-THIOUREA AND BROMOPHENYL [1-PHENYL-3-(1′,3′-THIAZOL-3′-IUM-2′-YL)-ISOTHIOUREIDATO]TELLURIUM(II)

Abstract The divalent tellurium title complex (II) has been synthesized by addition of Ph2Te2 and Br2 to the ligand 1-phenyl-3-(2-thiazolyl)-2-thiourea (I).The molecular structures of I and II were subsequently determined by X-ray crystallographic methods. As a result, it was found that upon complexation, the ligand had undergone a transition from a thiourea to to an isomeric isothiourea, involving a transfer of a thiourea proton to the thiazolyl ring. This does not seem to influence the bonding properties of the ligand, and the reasons for this are discussed. The central tellurium atom is three-coordinate and its coordination sphere is T-shaped with a linear S-Te-Br sequence with bond lengths Te(1)-S(1) and Te(1)-Br(1) equal to 2.548(1) and 2.883(1) A, respectively, and ∠ S(1)-Te(1)-Br(1)=174.49(2)°. At nearly right angles to this sequence, there is a Te(1)-C(11)(phenyl) bond of 2.127(3) A.

Bromobis(Diethyldithiocarbamato)(4-Methoxyphenyl)Tellurium(IV)

The crystals of the Te IV complex p-CH 3 OC 6 H 4 Te-(Et 2 NCS 2 ) 2 Br are isomorphous with those of the iodine and mixed iodine/bromine analogues previously investigated. The structure is pentagonal bipyramidal at the Te atom with four S atoms [Te-S 2.618-2.721 (1) A] and the Br atom [Te-Br 2.943 (1) A] in equatorial positions. The p-methoxyphenyl group is axial [Te-C 2.147(3) A]. The second axial position is approached by a Br atom of a centrosymmetrically related complex [Te...Br 3.423 (1) A, C-Te...Br 173.1 (1)°] so that the molecules are joined into centrosymmetric pairs by this weak secondary coordination.

Special Issue of Phosphorus, Sulfur, and Silicon and the Related Elements Dedicated to Professor Naomichi Furukawa

Greetings! It gives me immense pleasure to present this special issue of Phosphorus, Sulfur, and Silicon and the Related Elements that comprises 39 invited manuscripts dedicated to the achievements of Professor Naomichi Furukawa, now an Emeritus Professor of Chemistry at Tsukaba University. I would like to thank the many authors who have contributed excellent scientific manuscripts for publication and to my European Editor, Konstantin Karaghiosoff, for all of his work in getting the issue together through his editorial process. I would also like to thank Professors Jozef Drabowicz (Łodz, Poland) and Takeshi Akasaka (Tsukuba, Japan) for their organization as Guest Editors for this issue. Below you will find an invited tribute to the lifetime of contributions to main group chemistry from Professor Furukawa that has been written by Professors Drabowicz and Akasaka. I hope it begins to reveal some of the marvelous chemistry we have been fortunate enough to read in the articles that have been published by his group.